Strahlentherapie bei Melanom-Hautkrebs

Strahlentherapie bei Melanom-Hautkrebs Die Strahlentherapie setzt hochenergetische Strahlen (zB Röntgenstrahlen) oder Partikel um Krebszellen abzutöten. Externe Strahlentherapie fokussiert Strahlung von außerhalb des Körpers auf der Haut Tumor. Diese Art der Strahlentherapie wird verwendet, um einige Patienten mit Melanom zu behandeln. Vor der Behandlung beginnen, wird der Strahlungs Team sorgfältige Messungen nehmen, um die richtigen Winkel zur Ausrichtung der Strahlenbündel und die richtige Dosis der Strahlung zu bestimmen. Die Behandlung ist wie immer ein Röntgen, aber die Strahlung stärker. Das Verfahren selbst ist schmerzlos. Jede Behandlung dauert nur ein paar Minuten, auch wenn die Setup-Zeit - erhalten Sie an Ort und Stelle für die Behandlung - dauert in der Regel länger. Wann könnte der Strahlentherapie eingesetzt werden? Strahlentherapie wird nicht oft verwendet, um die ursprünglichen Melanom, die auf der Haut begann behandeln, obwohl sie manchmal nach einer Operation für einen Typ eines Melanom desmoplastischen Melanom bekannt ist. In einigen Fällen kann die Strahlung nach der Operation in dem Bereich, in Lymphknoten wurden entfernt gegeben werden, insbesondere, wenn viele Knoten enthalten Krebszellen. Dies ist zu versuchen, die Chance, dass der Krebs kommt zurück zu reduzieren. Die Strahlentherapie kann auch zur Behandlung von Melanomen, die wieder nach der Operation gekommen ist (Rückfall), entweder in den Haut oder Lymphknoten oder zur Unterstützung der Behandlung entfernten Ausbreitung der Krankheit werden. Strahlentherapie wird oft verwendet, um Symptome, die durch die Ausbreitung des Melanoms zu lindern, insbesondere des Gehirns oder Knochen. Die Behandlung mit dem Ziel der Linderung der Symptome wird als palliative Therapie. Palliative Strahlentherapie ist nicht zu erwarten, um den Krebs zu heilen, aber es könnte helfen, schrumpfen sie für eine Zeit, einige der Symptome zu kontrollieren. Stereotaktische Radiochirurgie (SRS) SRS ist eine Art von Strahlungstherapie, die manchmal für Tumore, die sich auf das Gehirn verwendet werden kann. (Trotz des Namens, gibt es keine eigentliche Operation beteiligt ist.) In einer Version dieser Behandlung eine weitere Maschine ein Gamma Knife® konzentriert etwa 200 Strahlen der Strahlung auf den Tumor aus verschiedenen Winkeln über ein paar Minuten bis zu Stunden. Der Kopf wird in der gleichen Position, indem sie in einem starren Rahmen gehalten. In einer anderen Version wird ein Linearbeschleuniger (eine Maschine, die eine Strahlung erzeugt), die von einem Computer bewegt sich um den Kopf gesteuert wird, um Strahlung auf den Tumor aus vielen verschiedenen Winkeln zu liefern. Diese Behandlungen können bei Bedarf wiederholt werden. Mögliche Nebenwirkungen der Strahlentherapie Häufige Nebenwirkungen sind abhängig von, wo die Strahlung ausgerichtet und können sein: Sonnenbrand-ähnlicher Hautproblemen Haarausfall, wo die Strahlung in den Körper Müdigkeit Übelkeit Appetitlosigkeit und Gewichtsverlust Oft werden diese verschwinden nach der Behandlung. Wenn Strahlung mit einer Chemotherapie, die Nebenwirkungen sind häufig schlechter. Die Strahlentherapie des Gehirns kann manchmal dazu führen, Gedächtnisverlust, Kopfschmerzen, Probleme zu denken, oder reduziert das sexuelle Verlangen. Normalerweise werden diese Symptome sind gering im Vergleich mit denen, die durch einen Tumor im Gehirn verursacht, aber sie können Ihre Lebensqualität zu reduzieren

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Lung Cancer

The body is made up of many types of cells. Normally, cells grow, divide, and produce more cells as needed to keep the body healthy and functioning properly. Sometimes, however, the process goes wrong and cells become abnormal, forming more cells in an uncontrolled way. These extra cells form a mass of tissue, called a growth or tumor. Tumors can be benign, which means not cancerous, or malignant, which means cancerous. Lung cancer occurs when a tumor forms in the tissue of the lung.

Lung cancer is the leading cause of cancer death in men and women in the United States. Experts estimate that there will be 215,020 new cases of lung cancer in 2008-- 114,690 cases in men and 100,330 cases in women. 161,840 Americans are expected to die of the disease 90,810 men and 71,030 women. Lung cancer occurs most often between the ages of 55 and 65.

There are two major types of lung cancer -- non-small cell lung cancer and small cell lung cancer. Each type of lung cancer grows and spreads in different ways, and each is treated differently. Non-small cell lung cancer is more common than small cell lung cancer. Small cell lung cancer, sometimes called oat cell cancer, grows more quickly and is more likely to spread to other organs in the body.

Lung cancer may spread to the lymph nodes or other tissues in the chest, including the lung opposite to where it originated. It may also spread to other organs of the body, such as the bones, brain, or liver. When cancer spreads from its original location in the lung to another part of the body such as the brain, it is called metastatic lung cancer, not brain cancer. Doctors sometimes call this distant disease.

Lung cancer would occur much less often if people did not smoke. The good news is that smoking is not as popular as it used to be. In 1965 about 42 percent of all adults smoked, but by 2008 only 21 percent did. Also, there has been a sharp drop in lung cancer deaths among men, mainly because fewer men are smoking.

The bad news is that smoking rates, which were dropping, have stopped declining in recent years. Smoking by young adults actually increased by 73 percent in the 1990s but has shown a downturn or leveling off in the past few years. Also, more women are getting lung cancer than ever before and more are dying from it, mainly because more young women are smoking -- however, this trend is also starting to reverse itself. Many smoking education programs now focus more directly on women and young people who smoke.

Lung Cancer in Women

Lung cancer in women differs from lung cancer in men in many ways. Yet, despite obvious differences in our appearance, we tend to lump men and women together when talking about lung cancer. This is unfortunate, since the causes, response to various treatments, survival rate, and even symptoms to watch for differ. What are some facts about lung cancer in women?
Statistics About Lung Cancer in Women
Lung cancer is the leading cause of cancer deaths in women, killing more women each year than breast cancer, uterine cancer, and ovarian cancer combined. While smoking is the number one cause, 20% of these women have never touched a cigarette.

Once considered a “man’s disease,” lung cancer is no longer discriminatory. In 2005, the last year for which we have statistics, 82,271 women (vs 107,416 men) were diagnosed with lung cancer, and 69,078 (vs 90,139 men) died.

While lung cancer diagnoses decreased each year from 1991-2005 for men, the incidence increased 0.5% each year for women. The reason for this is not completely clear.

Lung cancer in women occurs at a slightly younger age, and almost half of lung cancers in people under 50 occur in women.
Causes
Even though smoking is the number one cause of lung cancer in women, a higher percentage of women who develop lung cancer are life-long non-smokers. Some of the causes may include exposure to radon in our homes, secondhand smoke, other environmental and occupational exposures, or a genetic predisposition. Recent studies suggest infection with the human papilloma virus (HPV) may also play a role.
Smoking Status
Some, but not all, studies suggest that women may be more susceptible to the carcinogens in cigarettes, and women tend to develop lung cancer after fewer years of smoking.
Lung Cancer Types
Whereas men are more likely to develop squamous cell lung cancer, another form of non-small cell lung cancer, adenocarcinoma is the most common type of lung cancer found in women.

BAC (Bronchioalveolar carcinoma) is a rare form of lung cancer that is more common in women. For unknown reasons, the incidence of BAC appears to be increasing worldwide, especially among younger, non-smoking women.
Symptoms
We hear about the symptoms of a heart attack being different in women from in men. The same could hold true for lung cancer. Squamous cell lung cancer (the type more common in men) grows near the airways, and often presents with the “classic symptoms” of lung cancer, such as a cough and coughing up blood. Adenocarcinomas (the type of lung cancer that is more common in women), often develops in the outer regions of the lungs. These tumors can grow quite large or spread before they cause any symptoms. Symptoms of fatigue, the gradual onset of shortness of breath, or chest and back pain from the spread of lung cancer to bone, may be the first sign that something is wrong.

    More About Symptoms of Lung Cancer in Women

Lung Cancer in Women – The Role of Estrogen
It is likely that estrogen plays a role in the development and progression of lung cancer and research is being done to define this further. Women who have their ovaries removed surgically before menopause may be at higher risk of developing lung cancer. Recent research suggests that treatment with estrogen and progesterone (hormone replacement therapy) after menopause may increase the risk of dying from lung cancer (though it did not increase the risk of developing lung cancer).

    More About Estrogen and Lung Cancer

Treatment
Women historically respond to a few chemotherapy medications used for lung cancer better than men. One of the new targeted therapies, erlotinib (Tarceva), also appears to be more effective for women. Women who are able to be treated with surgery for lung cancer also tend to fair better. In one study, the median survival after surgery for lung cancer was twice as long for women as for men.

On the other hand, even though the National Cancer Institute recommends that all patients with stage 3 lung cancer be considered candidates for clinical trials, women are less likely to be involved in clinical trials than are men.
Survival
The survival rate for lung cancer in women is higher than for men at all stages of the disease. Sadly, the overall 5-year survival rate is only 16% (vs 12% for men).
Awareness and Funding
Even though many more women die from lung cancer than breast cancer, much more funding is devoted to breast cancer research than lung cancer research. According to the Lung Cancer Alliance, federal research funding in 2007 from the National Cancer Institute, Department of Defense, and Centers for Disease Control amounted to $23,754 per breast cancer death, and only $1,414 per lung cancer death. Due to a lower survival rate, and the symptoms of lung cancer (many survivors cannot walk and run for the cure), as well as the stigma, private fundraising also lags significantly behind that of breast cancer.
How Can Women Reduce Their Risk of Lung Cancer?
Thankfully, even though lung cancer is the leading cause of cancer deaths in women, it is a largely preventable disease:

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What Is Lung Cancer?What Is Lung Cancer?

The word cancer tends to strike fear into many people as it is associated with a severe illness that in the past many did not survive. Today treatment has improved dramatically, particularly with some forms of cancer. With continued research further improvements will be made.
The disease first manifests itself in our cells and our bodies are made up of millions of cells. Collectively they form our bones, muscles and organs.

A gene controls a cell and informs it as to what to do. This will include growing and reproducing and usually the cells follow the order. Sometimes instructions become confused and cells start growing and multiplying where they shouldn’t. These groups of cells can form into tumors or lumps and may spread through the bloodstream and lymphatic system (this is known as known as metastases).

The lumps or tumors fall into two categories; benign (non-cancerous) or malignant (cancerous). The difference being that benign tumor cells remain in one place and are not usually a concern.
Malignant tumor cells invade nearby tissues and spread to other parts of the body.
A swollen lymph node often provides the first sign that a malignant tumour has spread (metastasized). Quite often this occurs when a cancerous tumor is close by but cancer may metastasize to practically any part of the body and hence it is important that these type of tumors are found quickly.

The name of a particular cancer is basically defined by the part of the body where they grow. As an example a growth in the lung that spreads to the bladder is known as lung cancer with bladder metastases.

In lung cancer the cells of the lung are first involved.

The two main types of lung cancer are:

Non-small cell lung cancer (NSCLC). This is the most common type of lung cancer. It growth is slower than small cell lung cancer. Approximately 80% of lung cancers diagnosed are this type.

Small cell lung cancer (SCLC). This type invades quickly and will spread to other parts of the body.

NSCLC are groups of different cells and there are three types

Squamous cell carcinoma, this is often found in the central part of the lung.

Adenocarcinoma,this generally occurs in the outer part of the lung.

Large cell carcinoma, this can occur almost anywhere in the lung.
Although people with adenocarcinoma have a more favorable outlook, any non-small cell cancers can increase in size quickly and the prognosis can therefore be poor.

Treatment differs for each type of cancer as they do behave very differently. The treatment will depend on the staging of the disease.

Advanced stages of NSCLC may be treated by removal of the affected lung tissue to remove all or part of the tumour. While it may be possible to completely remove the tumor, this may not always be possible.

Chemotherapy and radiation treatment is common and administered after an operation or where the tumor is small enough for surgery not to be necessary. The patients general state of health also plays a part as treatments can be debilitating.

Chemotherapy and radiation are the only real options for those with SCLC and the results generally don’t provide remission but they are successful at extending the patient’s life.

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The risk of lung cancer

LUNG CANCER

  

The Lungs

The lungs are a pair of cone-shaped organs that are situated inside the chest. The lungs bring oxygen into the body and take out carbon dioxide, which is a waste product of the cells of the body.

Tubes called bronchi make up the inside of the lungs.

Your lungs have an extensive network of blood and lymph vessels. Cancer cells may grow into these vessels and be carried by the blood or lymph and be deposited elsewhere in the body.

Cancer can spread from the lungs to almost any site in the body. Most commonly it spreads to the brain, bone, bone marrow and liver. Lung cancer takes many years to develop. It is the second most common cancer in women.

There are two basic types of lung cancer - small cell and non-small cell cancer. These different types grow and spread in different ways. Small cell lung cancer is a disease in which cancer cells are found in the tissues of the lungs. It is usually found in people who smoke or who used to smoke cigarettes.

The non-small cell type of lung cancer is a common disease and is usually associated with people who used to smoke, passive smoking and radon (a radioactive gas) exposure.

SIGNS AND SYMPTOMS

These can include:

- hoarseness - persistent cough - blood in your phlegm - shortness of breath

- chest pain - loss of appetite - difficulty in swallowing - weakness - paleness

- high temperature - joint swelling - bone pain or tenderness - weight loss

Smoking causes about 85% of lung cancer cases. Cigarette smoke contains over 4,000 different chemicals, many of which are proven carcinogens (materials that are known to cause cancer). Lung cancer occurs most in people over 50 who have a long history of cigarette smoking.

RISK FACTORS

The risk of lung cancer increases, the more cigarettes smoked per day.

Also, the earlier the age at which smoking began, the greater the risk of lung cancer.

Passive smoking is also known to increase the risk.

In rare cases, exposure to certain industrial substances, such as arsenic, certain organic chemicals and asbestos.

Radiation exposure from occupational, medical and environmental sources.

EXAMINATIONS

If the patient has a persistent cough that produces phlegm, the phlegm will be examined for cancer cells.

The doctor may order a chest X-ray or a specialised X-ray such as the CAT scan, which helps to locate any abnormal spots in the lungs. A bronchoscopy may be performed. A bronchoscope is a small tube inserted through the nose or mouth, down the throat, into the bronchial tubes. During this examination, the doctor may also obtain a biopsy or other sample of lung tissue to test for cancer cells. Pressure is felt during the examination but very seldom pain.

TREATMENT

Surgery may cure lung cancer. It is used in early stages of the disease.

Radiation therapy can also be used.

This is used:

in a combination with chemotherapy and sometimes with surgery to offer relief from pain.

Chemotherapy may be used: in a combination with chemotherapy and sometimes with surgery to offer relief from pain.

along with surgery.

in more advanced stages of the cancer.

in all the stages of small cell cancer.

PREVENTION :

STOP SMOKING

Try to avoid second-hand smoke/passive smoking.

Ask questions about your work environment if you are exposed to industrial dusts and fumes, as it can be very dangerous.

How Lung Cancer Affects the Body

Types of Lung Cancer

      The type of lung cancer will determine how quickly it will spread and take a toll on the body.

      The types of lung cancer are treated differently. The most common types are named for how the lung cancer cells look under a microscope:

      Small cell lung cancer: About 13 percent of lung cancers are small cell lung cancers. This type tends to spread quickly.

      Non-small cell lung cancer: Most lung cancers, about 87 percent, are non-small cell lung cancers. This type spreads more slowly than small cell lung cancer.

      To find out what stage the cancer is in, your doctor will measure the lump, check to see if the cancer has spread and perform tests such as bone and lung scans and tissue or bone biopsies. The results of the tests will help you and your doctor decide on a treatment plan.

How Lung Cancer Affects the Body

    *

      Besides the symptoms of lung cancer, which are generally due to the direct effects of the primary tumor to effects of metastatic tumors in other parts of the body or to disturbances of hormones, blood or other systems caused by the cancer, there are other issues that affect the body due to treatment depending on the type of lung cancer and whether or not it is metastatic lung cancer. The effects on the body include:

      Lung cancer most often spreads to the liver, the adrenal glands, the bones and the brain.

      Metastatic lung cancer in the liver usually does not cause symptoms, at least by the time of diagnosis.

      Metastatic lung cancer in the adrenal glands also typically causes no symptoms by the time of diagnosis.

      Metastasis to the bones is most common with small cell cancers but also occurs with other lung cancer types. Lung cancer that has metastasized to the bone causes bone pain, usually in the backbone (vertebrae), the thighbones and the ribs.

      Lung cancer that spreads to the brain can cause difficulties with vision, weakness on one side of the body and/or seizures.

Radiation and Chemotherapy

    *

      Depending on the stage of the lung cancer and the growth of the tumor, the doctor may suggest chemotherapy or radiation.

      Chemotherapy uses chemicals that travel through the bloodstream. It affects both cancerous and healthy cells. This accounts for the many well-known side effects of chemotherapy, including nausea and vomiting, hair loss, skin problems, mouth sores and fatigue.

      Radiation therapy does not affect cells throughout the body the way chemotherapy does. However, it does affect healthy tissues overlying or directly adjacent to the tumor. To a certain extent, the side effects of radiation depend on which part of the body is targeted with radiation.

      Surgery is another alternative. It is the preferred treatment for patients with early stage NSCLC. Unfortunately, 60 to 80 percent of all patients who have advanced or metastatic disease are not suitable for surgery. Surgery has it benefits but it takes a toll on the patient. Many people experience pain, weakness, fatigue and shortness of breath after surgery. Most have problems moving around, coughing and breathing deeply. The recovery period can be several weeks or even months.

Lung Treatments

Lung Treatments

• Thoracotomy : A surgery that enters the chest wall (thorax). Thoracotomy may be done to treat some serious lung conditions or to obtain a lung biopsy.
• Video-assisted thorascopic surgery (VATS): Less-invasive chest wall surgery using an endoscope (flexible tube with a camera on its end). VATS may be used to treat or diagnose various lung conditions.
• Chest tube (thoracostomy): A tube is inserted through an incision in the chest wall in order to drain fluid or air from around the lung.
• Pleurocentesis: A needle is placed into the chest cavity to drain fluid that's around the lung. A sample is usually examined to identify the cause.
• Antibiotics : Medicines that kill bacteria are used to treat most cases of pneumonia. Antibiotics are not effective against viruses.
• Antiviral drugs : When used soon after flu symptoms start, antiviral medicines can reduce the severity of influenza. Antiviral drugs are not effective against viral bronchitis.
• Bronchodilators : Inhaled medicines can help expand the airways (bronchi). This can reduce wheezing and shortness of breath in people with asthma or COPD.
• Corticosteroids : Inhaled or oral steroids can reduce inflammation and improve symptoms in asthma or COPD. Steroids can also be used to treat less common lung conditions caused by inflammation.
• Mechanical ventilation: People with severe attacks of lung disease may require a machine called a ventilator to assist breathing. The ventilator pumps in air through a tube inserted into the mouth or the neck.
• Continuous positive airway pressure ( CPAP): Air pressure applied by a machine through a mask keeps the airways open. It is used at night to treat sleep apnea, but it is also helpful for some people with COPD.
• Lung transplant : Surgical removal of diseased lungs and replacement with organ donor lungs. Severe COPD, pulmonary hypertension, and pulmonary fibrosis are sometimes treated with lung transplant.
• Lung resection: A diseased portion of the lung is removed through surgery. Most often, lung resection is used to treat lung cancer.
• Vasodilators: People with some forms of pulmonary hypertension may require long-term medicines to lower the pressure in their lungs. Often, these must be taken through a continuous infusion into the veins.
• Chemotherapy and radiation therapy: Lung cancer is often not curable with surgery. Chemotherapy and radiation therapy can help improve symptoms and sometimes extend life with lung cancer.

How common is lung cancer?

Lung cancer is the most common cause of death due to cancer in both men and women throughout the world. The American Cancer Society estimates that 219,440 new cases of lung cancer in the U.S. will be diagnosed and 159,390 deaths due to lung cancer will occur in 2009. According to the U.S. National Cancer Institute, approximately one out of every 14 men and women in the U.S. will be diagnosed with cancer of the lung at some point in their lifetime.

Lung cancer is predominantly a disease of the elderly; almost 70% of people diagnosed with lung cancer are over 65 years of age, while less than 3% of lung cancers occur in people under 45 years of age.

Lung cancer was not common prior to the 1930s but increased dramatically over the following decades as tobacco smoking increased. In many developing countries, the incidence of lung cancer is beginning to fall following public education about the dangers of cigarette smoking and the introduction of effective smoking-cessation programs. Nevertheless, lung cancer remains among the most common types of cancers in both men and women worldwide. In the U.S., lung cancer has surpassed breast cancer as the most common cause of cancer-related deaths in women.

What causes lung cancer?

Smoking

The incidence of lung cancer is strongly correlated with cigarette smoking, with about 90% of lung cancers arising as a result of tobacco use. The risk of lung cancer increases with the number of cigarettes smoked and the time over which smoking has occurred; doctors refer to this risk in terms of pack-years of smoking history (the number of packs of cigarettes smoked per day multiplied by the number of years smoked). For example, a person who has smoked two packs of cigarettes per day for 10 years has a 20 pack-year smoking history. While the risk of lung cancer is increased with even a 10-pack-year smoking history, those with 30-pack-year histories or more are considered to have the greatest risk for the development of lung cancer. Among those who smoke two or more packs of cigarettes per day, one in seven will die of lung cancer.

Pipe and cigar smoking also can cause lung cancer, although the risk is not as high as with cigarette smoking. Thus, while someone who smokes one pack of cigarettes per day has a risk for the development of lung cancer that is 25 times higher than a nonsmoker, pipe and cigar smokers have a risk of lung cancer that is about five times that of a nonsmoker.

Tobacco smoke contains over 4,000 chemical compounds, many of which have been shown to be cancer-causing or carcinogenic. The two primary carcinogens in tobacco smoke are chemicals known as nitrosamines and polycyclic aromatic hydrocarbons. The risk of developing lung cancer decreases each year following smoking cessation as normal cells grow and replace damaged cells in the lung. In former smokers, the risk of developing lung cancer begins to approach that of a nonsmoker about 15 years after cessation of smoking.

Passive smoking

Passive smoking or the inhalation of tobacco smoke by nonsmokers who share living or working quarters with smokers, also is an established risk factor for the development of lung cancer. Research has shown that nonsmokers who reside with a smoker have a 24% increase in risk for developing lung cancer when compared with nonsmokers who do not reside with a smoker. An estimated 3,000 lung cancer deaths that occur each year in the U.S. are attributable to passive smoking.

Asbestos fibers

Asbestos fibers are silicate fibers that can persist for a lifetime in lung tissue following exposure to asbestos. The workplace is a common source of exposure to asbestos fibers, as asbestos was widely used in the past as both thermal and acoustic insulation. Today, asbestos use is limited or banned in many countries, including the U.S. Both lung cancer and mesothelioma (cancer of the pleura of the lung as well as of the lining of the abdominal cavity called the peritoneum) are associated with exposure to asbestos. Cigarette smoking drastically increases the chance of developing an asbestos-related lung cancer in workers exposed to asbestos. Asbestos workers who do not smoke have a fivefold greater risk of developing lung cancer than nonsmokers, but asbestos workers who smoke have a risk that is 50- to 90-fold greater than nonsmokers.

Radon gas

Radon gas is a natural, chemically inert gas that is a natural decay product of uranium. Uranium decays to form products, including radon, that emit a type of ionizing radiation. Radon gas is a known cause of lung cancer, with an estimated 12% of lung-cancer deaths attributable to radon gas, or about 20,000 lung-cancer-related deaths annually in the U.S., making radon the second leading cause of lung cancer in the U.S. As with asbestos exposure, concomitant smoking greatly increases the risk of lung cancer with radon exposure. Radon gas can travel up through soil and enter homes through gaps in the foundation, pipes, drains, or other openings. The U.S. Environmental Protection Agency estimates that one out of every 15 homes in the U.S. contains dangerous levels of radon gas. Radon gas is invisible and odorless, but it can be detected with simple test kits.

Familial predisposition

While the majority of lung cancers are associated with tobacco smoking, the fact that not all smokers eventually develop lung cancer suggests that other factors, such as individual genetic susceptibility, may play a role in the causation of lung cancer. Numerous studies have shown that lung cancer is more likely to occur in both smoking and non-smoking relatives of those who have had lung cancer than in the general population. Recently, the largest genetic study of lung cancer ever conducted, involving over 10,000 people from 18 countries and led by the International Agency for Research on Cancer (IARC), identified a small region in the genome (DNA) that contains genes that appear to confer an increased susceptibility to lung cancer in smokers. The specific genes, located the q arm of chromosome 15, code for proteins that interact with nicotine and other tobacco toxins (nicotinic acetylcholine receptor genes).

Lung diseases

The presence of certain diseases of the lung, notably chronic obstructive pulmonary disease (COPD), is associated with an increased risk (four- to sixfold the risk of a nonsmoker) for the development of lung cancer even after the effects of concomitant cigarette smoking are excluded.

Prior history of lung cancer

Survivors of lung cancer have a greater risk of developing a second lung cancer than the general population has of developing a first lung cancer. Survivors of non-small cell lung cancers (NSCLCs, see below) have an additive risk of 1%-2% per year for developing a second lung cancer. In survivors of small cell lung cancers (SCLCs, see below), the risk for development of second lung cancers approaches 6% per year.

Air pollution

Air pollution from vehicles, industry, and power plants can raise the likelihood of developing lung cancer in exposed individuals. Up to 1% of lung cancer deaths are attributable to breathing polluted air, and experts believe that prolonged exposure to highly polluted air can carry a risk for the development of lung cancer similar to that of passive smoking.

Lung Treatments

Lung Treatments

• Thoracotomy : A surgery that enters the chest wall (thorax). Thoracotomy may be done to treat some serious lung conditions or to obtain a lung biopsy.
• Video-assisted thorascopic surgery (VATS): Less-invasive chest wall surgery using an endoscope (flexible tube with a camera on its end). VATS may be used to treat or diagnose various lung conditions.
• Chest tube (thoracostomy): A tube is inserted through an incision in the chest wall in order to drain fluid or air from around the lung.
• Pleurocentesis: A needle is placed into the chest cavity to drain fluid that's around the lung. A sample is usually examined to identify the cause.
• Antibiotics : Medicines that kill bacteria are used to treat most cases of pneumonia. Antibiotics are not effective against viruses.
• Antiviral drugs : When used soon after flu symptoms start, antiviral medicines can reduce the severity of influenza. Antiviral drugs are not effective against viral bronchitis.
• Bronchodilators : Inhaled medicines can help expand the airways (bronchi). This can reduce wheezing and shortness of breath in people with asthma or COPD.
• Corticosteroids : Inhaled or oral steroids can reduce inflammation and improve symptoms in asthma or COPD. Steroids can also be used to treat less common lung conditions caused by inflammation.
• Mechanical ventilation: People with severe attacks of lung disease may require a machine called a ventilator to assist breathing. The ventilator pumps in air through a tube inserted into the mouth or the neck.
• Continuous positive airway pressure ( CPAP): Air pressure applied by a machine through a mask keeps the airways open. It is used at night to treat sleep apnea, but it is also helpful for some people with COPD.
• Lung transplant : Surgical removal of diseased lungs and replacement with organ donor lungs. Severe COPD, pulmonary hypertension, and pulmonary fibrosis are sometimes treated with lung transplant.
• Lung resection: A diseased portion of the lung is removed through surgery. Most often, lung resection is used to treat lung cancer.
• Vasodilators: People with some forms of pulmonary hypertension may require long-term medicines to lower the pressure in their lungs. Often, these must be taken through a continuous infusion into the veins.
• Chemotherapy and radiation therapy: Lung cancer is often not curable with surgery. Chemotherapy and radiation therapy can help improve symptoms and sometimes extend life with lung cancer.

What are the types of lung cancer?

Lung cancers, also known as bronchogenic carcinomas, are broadly classified into two types: small cell lung cancers (SCLC) and non-small cell lung cancers (NSCLC). This classification is based upon the microscopic appearance of the tumor cells themselves. These two types of cancers grow and spread in different ways and may have different treatment options, so a distinction between these two types is important.

SCLC comprise about 20% of lung cancers and are the most aggressive and rapidly growing of all lung cancers. SCLC are strongly related to cigarette smoking, with only 1% of these tumors occurring in nonsmokers. SCLC metastasize rapidly to many sites within the body and are most often discovered after they have spread extensively. Referring to a specific cell appearance often seen when examining samples of SCLC under the microscope, these cancers are sometimes called oat cell carcinomas.

NSCLC are the most common lung cancers, accounting for about 80% of all lung cancers. NSCLC can be divided into three main types that are named based upon the type of cells found in the tumor:

• Adenocarcinomas are the most commonly seen type of NSCLC in the U.S. and comprise up to 50% of NSCLC. While adenocarcinomas are associated with smoking, like other lung cancers, this type is observed as well in nonsmokers who develop lung cancer. Most adenocarcinomas arise in the outer, or peripheral, areas of the lungs. Bronchioloalveolar carcinoma is a subtype of adenocarcinoma that frequently develops at multiple sites in the lungs and spreads along the preexisting alveolar walls.
• Squamous cell carcinomas were formerly more common than adenocarcinomas; at present, they account for about 30% of NSCLC. Also known as epidermoid carcinomas, squamous cell cancers arise most frequently in the central chest area in the bronchi.
• Large cell carcinomas, sometimes referred to as undifferentiated carcinomas, are the least common type of NSCLC.
• Mixtures of different types of NSCLC are also seen.

Other types of cancers can arise in the lung; these types are much less common than NSCLC and SCLC and together comprise only 5%-10% of lung cancers:

• Bronchial carcinoids account for up to 5% of lung cancers. These tumors are generally small (3-4 cm or less) when diagnosed and occur most commonly in people under 40 years of age. Unrelated to cigarette smoking, carcinoid tumors can metastasize, and a small proportion of these tumors secrete hormone-like substances that may cause specific symptoms related to the hormone being produced. Carcinoids generally grow and spread more slowly than bronchogenic cancers, and many are detected early enough to be amenable to surgical resection.
• Cancers of supporting lung tissue such as smooth muscle, blood vessels, or cells involved in the immune response can rarely occur in the lung.

As discussed previously, metastatic cancers from other primary tumors in the body are often found in the lung. Tumors from anywhere in the body may spread to the lungs either through the bloodstream, through the lymphatic system, or directly from nearby organs. Metastatic tumors are most often multiple, scattered throughout the lung, and concentrated in the peripheral rather than central areas of the lung.

Lung Cancer (cont.)

How can lung cancer be prevented?

Cessation of smoking is the most important measure that can prevent lung cancer. Many products, such as nicotine gum, nicotine sprays, or nicotine inhalers, may be helpful to people trying to quit smoking. Minimizing exposure to passive smoking also is an effective preventive measure. Using a home radon test kit can identify and allow correction of increased radon levels in the home. Methods that allow early detection of cancers, such as the helical low-dose CT scan, also may be of value in the identification of small cancers that can be cured by surgical resection and prevented from becoming widespread, incurable, metastatic cancer.

Lung Cancer At A Glance

• Lung cancer is the number-one cause of cancer deaths in both men and women in the U.S. and worldwide.
• Cigarette smoking is the principal risk factor for development of lung cancer.
• Passive exposure to tobacco smoke also can cause lung cancer.
• The two types of lung cancer, which grow and spread differently, are the small cell lung cancers (SCLC) and non-small cell lung cancers (NSCLC).
• The stage of lung cancer refers to the extent to which the cancer has spread in the body.
• Treatment of lung cancer can involve a combination of surgery, chemotherapy, and radiation therapy as well as newer experimental methods.
• The general prognosis of lung cancer is poor, with overall survival rates of about 16% at five years.
• Smoking cessation is the most important measure that can prevent the development of lung cancer.

Lung Tests

Lung Tests

• Chest X-ray : An X-ray is the most common first test for lung problems. It can identify air or fluid in the chest, fluid in the lung, pneumonia, masses, foreign bodies, and other problems.
• Computed tomography ( CT scan): A CT scan uses X-rays and a computer to make detailed pictures of the lungs and nearby structures.
• Pulmonary function tests (PFTs): A series of tests to evaluate how well the lungs work. Lung capacity, the ability to exhale forcefully, and the ability to transfer air between the lungs and blood are usually tested.
• Spirometry: Part of PFTs measures how fast and how much air you can breathe out.
• Sputum culture : Culturing mucus coughed up from the lungs can sometimes identify the organism responsible for a pneumonia or bronchitis.
• Sputum cytology : Viewing sputum under a microscope for abnormal cells can help diagnose lung cancer and other conditions.
• Lung biopsy : A small piece of tissue is taken from the lungs, either through bronchoscopy or surgery. Examining the biopsied tissue under a microscope can help diagnose lung conditions.
• Flexible bronchoscopy : An endoscope (flexible tube with a lighted camera on its end) is passed through the nose or mouth into the airways (bronchi). A doctor can take biopsies or samples for culture during bronchoscopy.
• Rigid bronchoscopy : A rigid metal tube is introduced through the mouth into the lungs' airways. Rigid bronchoscopy is often more effective than flexible bronchoscopy, but it requires general (total) anesthesia.
• Magnetic resonance imaging (MRI scan): An MRI scanner uses radio waves in a magnetic field to create high-resolution images of structures inside the chest.

 

Picture of the Lungs 

The lungs are a pair of spongy, air-filled organs located on either side of the chest (thorax). The trachea (windpipe) conducts inhaled air into the lungs through its tubular branches, called bronchi. The bronchi then divide into smaller and smaller branches (bronchioles), finally becoming microscopic.
The bronchioles eventually end in clusters of microscopic air sacs called alveoli. In the alveoli, oxygen from the air is absorbed into the blood. Carbon dioxide, a waste product of metabolism, travels from the blood to the alveoli, where it can be exhaled. Between the alveoli is a thin layer of cells called the interstitium, which contains blood vessels and cells that help support the alveoli.
The lungs are covered by a thin tissue layer called the pleura. The same kind of thin tissue lines the inside of the chest cavity -- also called pleura. A thin layer of fluid acts as a lubricant allowing the lungs to slip smoothly as they expand and contract with each breath.

Lung Conditions

• Chronic obstructive pulmonary disease (COPD): Damage to the lungs results in difficulty blowing air out, causing shortness of breath. Smoking is by far the most common cause of COPD.
• Emphysema : A form of COPD usually caused by smoking. The fragile walls between the lungs' air sacs (alveoli) are damaged, trapping air in the lungs and making breathing difficult.
• Chronic bronchitis : Repeated, frequent episodes of productive cough, usually caused by smoking. Breathing also becomes difficult in this form of COPD.
• Pneumonia : Infection in one or both lungs. Bacteria, especially Streptococcus pneumoniae, are the most common cause.
• Asthma : The lungs' airways (bronchi) become inflamed and can spasm, causing shortness of breath and wheezing. Allergies, viral infections, or air pollution often trigger asthma symptoms.
• Acute bronchitis : An infection of the lungs' large airways (bronchi), usually caused by a virus. Cough is the main symptom of acute bronchitis.
• Pulmonary fibrosis : A form of interstitial lung disease. The interstitium (walls between air sacs) become scarred, making the lungs stiff and causing shortness of breath.
• Sarcoidosis : Tiny areas of inflammation can affect all organs in the body, with the lungs involved most of the time. The symptoms are usually mild; sarcoidosis is usually found when X-rays are done for other reasons.
• Obesity hypoventilation syndrome: Extra weight makes it difficult to expand the chest when breathing. This can lead to long-term breathing problems.
  Pleural effusion: Fluid builds up in the normally tiny space between the lung and the inside of the chest wall (the pleural space). If large, pleural effusions can cause problems with breathing.
• Pleurisy : Inflammation of the lining of the lung (pleura), which often causes pain when breathing in. Autoimmune conditions, infections, or a pulmonary embolism may cause pleurisy.
• Bronchiectasis: The airways (bronchi) become inflamed and expand abnormally, usually after repeated infections. Coughing, with large amounts of mucus, is the main symptom of bronchiectasis.
• Lymphangioleiomyomatosis ( LAM): A rare condition in which cysts form throughout the lungs, causing breathing problems similar to emphysema. LAM occurs almost exclusively in women of childbearing age.
• Cystic fibrosis : A genetic condition in which mucus does not clear easily from the airways. The excess mucus causes repeated episodes of bronchitis and pneumonia throughout life.
• Interstitial lung disease: A collection of conditions in which the interstitium (lining between the air sacs) becomes diseased. Fibrosis (scarring) of the interstitium eventually results, if the process can't be stopped.
• Lung cancer : Cancer may affect almost any part of the lung. Most lung cancer is caused by smoking.
• Tuberculosis : A slowly progressive pneumonia caused by the bacteria Mycobacterium tuberculosis. Chronic cough, fever, weight loss, and night sweats are common symptoms of tuberculosis.
• Acute respiratory distress syndrome ( ARDS): Severe, sudden injury to the lungs caused by a serious illness. Life support with mechanical ventilation is usually needed to survive until the lungs recover.
• Coccidioidomycosis: A pneumonia caused by Coccidioides, a fungus found in the soil in the southwestern U.S. Most people experience no symptoms, or a flu-like illness with complete recovery.
• Histoplasmosis : An infection caused by inhaling Histoplasma capsulatum, a fungus found in the soil in the eastern and central U.S. Most Histoplasma pneumonias are mild, causing only a short-lived cough and flu-like symptoms.
• Hypersensitivity pneumonitis (allergic alveolitis): Inhaled dust causes an allergic reaction in the lungs. Usually this occurs in farmers or others who work with dried, dusty plant material.
• Influenza (flu): An infection by one or more flu viruses causes fever, body aches, and coughing lasting a week or more. Influenza can progress to life-threatening pneumonia, especially in older people with medical problems.
• Mesothelioma: A rare form of cancer that forms from the cells lining various organs of the body with the lungs being the most common. Mesothelioma tends to emerge several decades after asbestos exposure.
• Pertussis (whooping cough): A highly contagious infection of the airways (bronchi) by Bordetella pertussis, causing persistent cough. A booster vaccine (Tdap) is recommended for adolescents and adults to prevent pertussis.
• Pulmonary hypertension: Many conditions can lead to high blood pressure in the arteries leading from the heart to the lungs. If no cause can be identified, the condition is called idiopathic pulmonary arterial hypertension.
• Pulmonary embolism : A blood clot (usually from a vein in the leg) may break off and travel to the heart, which pumps the clot (embolus) into the lungs. Sudden shortness of breath is the most common symptom of a pulmonary embolism.
• Severe acute respiratory syndrome ( SARS): A severe pneumonia caused by a specific virus first discovered in Asia in 2002. Worldwide prevention measures seem to have controlled SARS, which has caused no deaths in the U.S.
• Pneumothorax: Air in the chest; it occurs when air enters the area around the lung (the pleural space) abnormally. Pneumothorax can be caused by an injury or may happen spontaneously.

What is the prognosis (outcome) of lung cancer?

The prognosis of lung cancer refers to the chance for cure or prolongation of life (survival) and is dependent upon where the cancer is located, the size of the cancer, the presence of symptoms, the type of lung cancer, and the overall health status of the patient.

SCLC has the most aggressive growth of all lung cancers, with a median survival time of only two to four months after diagnosis when untreated. (That is, by two to four months, half of all patients have died.) However, SCLC is also the type of lung cancer most responsive to radiation therapy and chemotherapy. Because SCLC spreads rapidly and is usually disseminated at the time of diagnosis, methods such as surgical removal or localized radiation therapy are less effective in treating this type of lung cancer. When chemotherapy is used alone or in combination with other methods, survival time can be prolonged four- to fivefold; however, of all patients with SCLC, only 5%-10% are still alive five years after diagnosis. Most of those who survive have limited-stage SCLC.

In non-small cell lung cancer (NSCLC), results of standard treatment are generally poor in all but the most smallest of cancers that can be surgically removed. However, in stage I cancers that can be completely removed surgically, five-year survival approaches 75%. Radiation therapy can produce a cure in a small minority of patients with NSCLC and leads to relief of symptoms in most patients. In advanced-stage disease, chemotherapy offers modest improvements in survival although rates of overall survival are poor.

The overall prognosis for lung cancer is poor when compared with some other cancers. Survival rates for lung cancer are generally lower than those for most cancers, with an overall five-year survival rate for lung cancer of about 16% compared to 65% for colon cancer, 89% for breast cancer, and over 99% for prostate cancer.

What is staging of lung cancer?

The stage of a cancer is a measure of the extent to which a cancer has spread in the body. Staging involves evaluation of a cancer's size and its penetration into surrounding tissue as well as the presence or absence of metastases in the lymph nodes or other organs. Staging is important for determining how a particular cancer should be treated, since lung-cancer therapies are geared toward specific stages. Staging of a cancer also is critical in estimating the prognosis of a given patient, with higher-stage cancers generally having a worse prognosis than lower-stage cancers.

Doctors may use several tests to accurately stage a lung cancer, including laboratory (blood chemistry) tests, X-rays, CT scans, bone scans, MRI scans, and PET scans. Abnormal blood chemistry tests may signal the presence of metastases in bone or liver, and radiological procedures can document the size of a cancer as well as its spread.

NSCLC are assigned a stage from I to IV in order of severity:

• In stage I, the cancer is confined to the lung.
• In stages II and III, the cancer is confined to the chest (with larger and more invasive tumors classified as stage III).
• Stage IV cancer has spread from the chest to other parts of the body.

SCLC are staged using a two-tiered system:

• Limited-stage (LS) SCLC refers to cancer that is confined to its area of origin in the chest.
• In extensive-stage (ES) SCLC, the cancer has spread beyond the chest to other parts of the body.

How is lung cancer treated?

Treatment for lung cancer can involve surgical removal of the cancer, chemotherapy, or radiation therapy, as well as combinations of these treatments. The decision about which treatments will be appropriate for a given individual must take into account the location and extent of the tumor as well as the overall health status of the patient.

As with other cancers, therapy may be prescribed that is intended to be curative (removal or eradication of a cancer) or palliative (measures that are unable to cure a cancer but can reduce pain and suffering). More than one type of therapy may be prescribed. In such cases, the therapy that is added to enhance the effects of the primary therapy is referred to as adjuvant therapy. An example of adjuvant therapy is chemotherapy or radiotherapy administered after surgical removal of a tumor in an attempt to kill any tumor cells that remain following surgery.

Surgery: Surgical removal of the tumor is generally performed for limited-stage (stage I or sometimes stage II) NSCLC and is the treatment of choice for cancer that has not spread beyond the lung. About 10%-35% of lung cancers can be removed surgically, but removal does not always result in a cure, since the tumors may already have spread and can recur at a later time. Among people who have an isolated, slow-growing lung cancer removed, 25%-40% are still alive five years after diagnosis. Surgery may not be possible if the cancer is too close to the trachea or if the person has other serious conditions (such as severe heart or lung disease) that would limit their ability to tolerate an operation. Surgery is less often performed with SCLC because these tumors are less likely to be localized to one area that can be removed.

The surgical procedure chosen depends upon the size and location of the tumor. Surgeons must open the chest wall and may perform a wedge resection of the lung (removal of a portion of one lobe), a lobectomy (removal of one lobe), or a pneumonectomy (removal of an entire lung). Sometimes lymph nodes in the region of the lungs also are removed (lymphadenectomy). Surgery for lung cancer is a major surgical procedure that requires general anesthesia, hospitalization, and follow-up care for weeks to months. Following the surgical procedure, patients may experience difficulty breathing, shortness of breath, pain, and weakness. The risks of surgery include complications due to bleeding, infection, and complications of general anesthesia.

Radiation: Radiation therapy may be employed as a treatment for both NSCLC and SCLC. Radiation therapy uses high-energy X-rays or other types of radiation to kill dividing cancer cells. Radiation therapy may be given as curative therapy, palliative therapy (using lower doses of radiation than with curative therapy), or as adjuvant therapy in combination with surgery or chemotherapy. The radiation is either delivered externally, by using a machine that directs radiation toward the cancer, or internally through placement of radioactive substances in sealed containers within the area of the body where the tumor is localized. Brachytherapy is a term used to describe the use of a small pellet of radioactive material placed directly into the cancer or into the airway next to the cancer. This is usually done through a bronchoscope.

Radiation therapy can be given if a person refuses surgery, if a tumor has spread to areas such as the lymph nodes or trachea making surgical removal impossible, or if a person has other conditions that make them too ill to undergo major surgery. Radiation therapy generally only shrinks a tumor or limits its growth when given as a sole therapy, yet in 10%-15% of people it leads to long-term remission and palliation of the cancer. Combining radiation therapy with chemotherapy can further prolong survival when chemotherapy is administered. External radiation therapy can generally be carried out on an outpatient basis, while internal radiation therapy requires a brief hospitalization. A person who has severe lung disease in addition to a lung cancer may not be able to receive radiotherapy to the lung since the radiation can further decrease function of the lungs. A type of external radiation therapy called the "gamma knife" is sometimes used to treat single brain metastases. In this procedure, multiple beams of radiation coming from different directions are focused on the tumor over a few minutes to hours while the head is held in place by a rigid frame. This reduces the dose of radiation that is received by noncancerous tissues.

For external radiation therapy, a process called simulation is necessary prior to treatment. Using CT scans, computers, and precise measurements, simulation maps out the exact location where the radiation will be delivered, called the treatment field or port. This process usually takes 30 minutes to two hours. The external radiation treatment itself generally is done four or five days a week for several weeks.

Radiation therapy does not carry the risks of major surgery, but it can have unpleasant side effects, including fatigue and lack of energy. A reduced white blood cell count (rendering a person more susceptible to infection) and low blood platelet levels (making blood clotting more difficult and resulting in excessive bleeding) also can occur with radiation therapy. If the digestive organs are in the field exposed to radiation, patients may experience nausea, vomiting, or diarrhea. Radiation therapy can irritate the skin in the area that is treated, but this irritation generally improves with time after treatment has ended.

Chemotherapy: Both NSCLC and SCLC may be treated with chemotherapy. Chemotherapy refers to the administration of drugs that stop the growth of cancer cells by killing them or preventing them from dividing. Chemotherapy may be given alone, as an adjuvant to surgical therapy, or in combination with radiotherapy. While a number of chemotherapeutic drugs have been developed, the class of drugs known as the platinum-based drugs have been the most effective in treatment of lung cancers.

Chemotherapy is the treatment of choice for most SCLC, since these tumors are generally widespread in the body when they are diagnosed. Only half of people who have SCLC survive for four months without chemotherapy. With chemotherapy, their survival time is increased up to four- to fivefold. Chemotherapy alone is not particularly effective in treating NSCLC, but when NSCLC has metastasized, it can prolong survival in many cases.

Chemotherapy may be given as pills, as an intravenous infusion, or as a combination of the two. Chemotherapy treatments usually are given in an outpatient setting. A combination of drugs is given in a series of treatments, called cycles, over a period of weeks to months, with breaks in between cycles. Unfortunately, the drugs used in chemotherapy also kill normally dividing cells in the body, resulting in unpleasant side effects. Damage to blood cells can result in increased susceptibility to infections and difficulties with blood clotting (bleeding or bruising easily). Other side effects include fatigue, weight loss, hair loss, nausea, vomiting, diarrhea, and mouth sores. The side effects of chemotherapy vary according to the dosage and combination of drugs used and may also vary from individual to individual. Medications have been developed that can treat or prevent many of the side effects of chemotherapy. The side effects generally disappear during the recovery phase of the treatment or after its completion.

Prophylactic brain radiation: SCLC often spreads to the brain. Sometimes people with SCLC that is responding well to treatment are treated with radiation therapy to the head to treat very early spread to the brain (called micrometastasis) that is not yet detectable with CT or MRI scans and has not yet produced symptoms. Brain radiation therapy can cause short-term memory problems, fatigue, nausea, and other side effects.

Treatment of recurrence: Lung cancer that has returned following treatment with surgery, chemotherapy, and/or radiation therapy is referred to as recurrent or relapsed. If a recurrent cancer is confined to one site in the lung, it may be treated with surgery. Recurrent tumors generally do not respond to the chemotherapeutic drugs that were previously administered. Since platinum-based drugs are generally used in initial chemotherapy of lung cancers, these agents are not useful in most cases of recurrence. A type of chemotherapy referred to as second-line chemotherapy is used to treat recurrent cancers that have previously been treated with chemotherapy, and a number of second-line chemotherapeutic regimens have been proven effective at prolonging survival. People with recurrent lung cancer who are well enough to tolerate therapy also are good candidates for experimental therapies (see below), including clinical trials.

Targeted therapy: One alternative to standard chemotherapy is the drug erlotinib (Tarceva), which may be used in patients with NSCLC who are no longer responding to chemotherapy. It is a so-called targeted drug, a drug that more specifically targets cancer cells, resulting in less damage to normal cells. Erlotinib targets a protein called the epidermal growth factor receptor (EGFR) that is important in promoting the division of cells. This protein is found at abnormally high levels on the surface of some types of cancer cells, including many cases of non-small cell lung cancer. Erlotinib is taken by mouth in pill form.

Other attempts at targeted therapy include drugs known as antiangiogenesis drugs, which block the development of new blood vessels within a cancer. Without adequate blood vessels to supply oxygen-carrying blood, the cancer cells will die. The antiangiogenic drug bevacizumab (Avastin) has recently been found to prolong survival in advanced lung cancer when it is added to the standard chemotherapy regimen. Bevacizumab is given intravenously every two to three weeks. However, since this drug may cause bleeding, it is not appropriate for use in patients who are coughing up blood, if the lung cancer has spread to the brain, or in people who are receiving anticoagulation therapy ("blood thinner" medications). Bevacizumab also is not used in cases of squamous cell cancer because it leads to bleeding from this type of lung cancer.

Vadimezan is a newer, experimental medication that disrupts blood vessels within tumors and thereby inhibits blood flow to the tumor. Vadimezan with its different way of acting on the blood vessels than bevacizumab seems to have fewer side effects. It also was shown in preliminary studies that vadimezan prolonged survival in patients receiving chemotherapy for NSCLC. Research still is under way to further characterize the safety and effectiveness of this newer drug.

Photodynamic therapy (PDT): One newer therapy used for different types and stages of lung cancer (as well as some other cancers) is photodynamic therapy. In photodynamic treatment, a photosynthesizing agent (such as a porphyrin, a naturally occurring substance in the body) is injected into the bloodstream a few hours prior to surgery. During this time, the agent is taken up in rapidly growing cells such as cancer cells. A procedure then follows in which the physician applies a certain wavelength of light through a handheld wand directly to the site of the cancer and surrounding tissues. The energy from the light activates the photosensitizing agent, causing the production of a toxin that destroys the tumor cells. PDT has the advantages that it can precisely target the location of the cancer, is less invasive than surgery, and can be repeated at the same site if necessary. The drawbacks of PDT are that it is only useful in treating cancers that can be reached with a light source and is not suitable for treatment of extensive cancers. Research is ongoing to further determine the effectiveness of PDT in lung cancer.

Radiofrequency ablation (RFA): Radiofrequency ablation is being studied as an alternative to surgery, particularly in cases of early stage lung cancer. In this newer type of treatment, a needle is inserted through the skin into the cancer, usually under guidance by CT scanning. Radiofrequency (electrical) energy is then transmitted to the tip of the needle where it produces heat in the tissues, killing the cancerous tissue and closing small blood vessels that supply the cancer. RFA usually is not painful and has been approved by the U.S. Food and Drug Administration for the treatment of certain cancers, including lung cancers. Studies have shown that this treatment can prolong survival similarly to surgery when used to treat early stages of lung cancer but without the risks of major surgery and the prolonged recovery time associated with major surgical procedures.

Experimental therapies: Since no therapy is currently available that is absolutely effective in treating lung cancer, patients may be offered a number of new therapies that are still in the experimental stage, meaning that doctors do not yet have enough information to decide whether these therapies should become accepted forms of treatment for lung cancer. New drugs or new combinations of drugs are tested in so-called clinical trials, which are studies that evaluate the effectiveness of new medications in comparison with those treatments already in widespread use. Experimental treatments known as immunotherapies are being studied that involve the use of vaccine-related therapies or other therapies that attempt to utilize the body's immune system to fight cancer cells.

How is lung cancer diagnosed?

Doctors use a wide range of diagnostic procedures and tests to diagnose lung cancer. These include...

• The history and physical examination may reveal the presence of symptoms or signs that are suspicious for lung cancer. In addition to asking about symptoms and risk factors for cancer development such as smoking, doctors may detect signs of breathing difficulties, airway obstruction, or infections in the lungs. Cyanosis, a bluish color of the skin and the mucous membranes due to insufficient oxygen in the blood, suggests compromised function due to chronic disease of the lung. Likewise, changes in the tissue of the nail beds, known as clubbing, also may indicate chronic lung disease.
• The chest X-ray is the most common first diagnostic step when any new symptoms of lung cancer are present. The chest X-ray procedure often involves a view from the back to the front of the chest as well as a view from the side. Like any X-ray procedure, chest X-rays expose the patient briefly to a small amount of radiation. Chest X-rays may reveal suspicious areas in the lungs but are unable to determine if these areas are cancerous. In particular, calcified nodules in the lungs or benign tumors called hamartomas may be identified on a chest X-ray and mimic lung cancer.
• CT (computerized tomography, computerized axial tomography, or CAT) scans may be performed on the chest, abdomen, and/or brain to examine for both metastatic and lung tumors. A CT scan of the chest may be ordered when X-rays do not show an abnormality or do not yield sufficient information about the extent or location of a tumor. CT scans are X-ray procedures that combine multiple images with the aid of a computer to generate cross-sectional views of the body. The images are taken by a large donut-shaped X-ray machine at different angles around the body. One advantage of CT scans is that they are more sensitive than standard chest X-rays in the detection of lung nodules, that is, they will demonstrate more nodules. Sometimes intravenous contrast material is given prior to the scan to help delineate the organs and their positions. A CT scan exposes the patient to a minimal amount of radiation. The most common side effect is an adverse reaction to intravenous contrast material that may have been given prior to the procedure. This may result in itching, a rash, or hives that generally disappear rather quickly. Severe anaphylactic reactions (life-threatening allergic reactions with breathing difficulties) to contrast material are rare. CT scans of the abdomen may identify metastatic cancer in the liver or adrenal glands, and CT scans of the head may be ordered to reveal the presence and extent of metastatic cancer in the brain.
• A technique called a low-dose helical CT scan (or spiral CT scan) is sometimes used in screening for lung cancers. This procedure requires a special type of CT scanner and has been shown to be an effective tool for the identification of small lung cancers in smokers and former smokers. However, it has not yet been proven whether the use of this technique actually saves lives or lowers the risk of death from lung cancer. The heightened sensitivity of this method is actually one of the sources of its drawbacks, since lung nodules requiring further evaluation will be seen in approximately 20% of people with this technique. Of the nodules identified by low-dose helical screening CTs, 90% are not cancerous but require up to two years of costly and often uncomfortable follow-up and testing. Trials are underway to further determine the utility of spiral CT scans in screening for lung cancer.
• Magnetic resonance imaging (MRI) scans may be appropriate when precise detail about a tumor's location is required. The MRI technique uses magnetism, radio waves, and a computer to produce images of body structures. As with CT scanning, the patient is placed on a moveable bed which is inserted into the MRI scanner. There are no known side effects of MRI scanning, and there is no exposure to radiation. The image and resolution produced by MRI is quite detailed and can detect tiny changes of structures within the body. People with heart pacemakers, metal implants, artificial heart valves, and other surgically implanted structures cannot be scanned with an MRI because of the risk that the magnet may move the metal parts of these structures.
• Positron emission tomography (PET) scanning is a specialized imaging technique that uses short-lived radioactive drugs to produce three-dimensional colored images of those substances in the tissues within the body. While CT scans and MRI scans look at anatomical structures, PET scans measure metabolic activity and the function of tissues. PET scans can determine whether a tumor tissue is actively growing and can aid in determining the type of cells within a particular tumor. In PET scanning, the patient receives a short half-lived radioactive drug, receiving approximately the amount of radiation exposure as two chest X-rays. The drug accumulates in certain tissues more than others, depending on the drug that is injected. The drug discharges particles known as positrons from whatever tissues take them up. As the positrons encounter electrons within the body, a reaction producing gamma rays occurs. A scanner records these gamma rays and maps the area where the radioactive drug has accumulated. For example, combining glucose (a common energy source in the body) with a radioactive substance will show where glucose is rapidly being used, for example, in a growing tumor.
• Bone scans are used to create images of bones on a computer screen or on film. Doctors may order a bone scan to determine whether a lung cancer has metastasized to the bones. In a bone scan, a small amount of radioactive material is injected into the bloodstream and collects in the bones, especially in abnormal areas such as those involved by metastatic tumors. The radioactive material is detected by a scanner, and the image of the bones is recorded on a special film for permanent viewing.
• Sputum cytology: The diagnosis of lung cancer always requires confirmation of malignant cells by a pathologist, even when symptoms and X-ray studies are suspicious for lung cancer. The simplest method to establish the diagnosis is the examination of sputum under a microscope. If a tumor is centrally located and has invaded the airways, this procedure, known as a sputum cytology examination, may allow visualization of tumor cells for diagnosis. This is the most risk-free and inexpensive tissue diagnostic procedure, but its value is limited since tumor cells will not always be present in sputum even if a cancer is present. Also, noncancerous cells may occasionally undergo changes in reaction to inflammation or injury that makes them look like cancer cells.
• Bronchoscopy: Examination of the airways by bronchoscopy (visualizing the airways through a thin, fiberoptic probe inserted through the nose or mouth) may reveal areas of tumor that can be sampled (biopsied) for diagnosis by a pathologist. A tumor in the central areas of the lung or arising from the larger airways is accessible to sampling using this technique. Bronchoscopy may be performed using a rigid or a flexible fiberoptic bronchoscope and can be performed in a same-day outpatient bronchoscopy suite, an operating room, or on a hospital ward. The procedure can be uncomfortable, and it requires sedation or anesthesia. While bronchoscopy is relatively safe, it must be carried out by a lung specialist (pulmonologist or surgeon) experienced in the procedure. When a tumor is visualized and adequately sampled, an accurate cancer diagnosis usually is possible. Some patients may cough up dark-brown blood for one to two days after the procedure. More serious but rare complications include a greater amount of bleeding, decreased levels of oxygen in the blood, and heart arrhythmias as well as complications from sedative medications and anesthesia.
• Needle biopsy: Fine needle aspiration (FNA) through the skin, most commonly performed with radiological imaging for guidance, may be useful in retrieving cells for diagnosis from tumor nodules in the lungs. Needle biopsies are particularly useful when the lung tumor is peripherally located in the lung and not accessible to sampling by bronchoscopy. A small amount of local anesthetic is given prior to insertion of a thin needle through the chest wall into the abnormal area in the lung. Cells are suctioned into the syringe and are examined under the microscope for tumor cells. This procedure is generally accurate when the tissue from the affected area is adequately sampled, but in some cases, adjacent or uninvolved areas of the lung may be mistakenly sampled. A small risk (3%-5%) of an air leak from the lungs (called a pneumothorax, which can easily be treated) accompanies the procedure.
• Thoracentesis: Sometimes lung cancers involve the lining tissue of the lungs (pleura) and lead to an accumulation of fluid in the space between the lungs and chest wall (called a pleural effusion). Aspiration of a sample of this fluid with a thin needle (thoracentesis) may reveal the cancer cells and establish the diagnosis. As with the needle biopsy, a small risk of a pneumothorax is associated with this procedure.
• Major surgical procedures: If none of the aforementioned methods yields a diagnosis, surgical methods must be employed to obtain tumor tissue for diagnosis. These can include mediastinoscopy (examining the chest cavity between the lungs through a surgically inserted probe with biopsy of tumor masses or lymph nodes that may contain metastases) or thoracotomy (surgical opening of the chest wall for removal or biopsy of a tumor). With a thoracotomy, it is rare to be able to completely remove a lung cancer, and both mediastinoscopy and thoracotomy carry the risks of major surgical procedures (complications such as bleeding, infection, and risks from anesthesia and medications). These procedures are performed in an operating room, and the patient must be hospitalized.
• Blood tests: While routine blood tests alone cannot diagnose lung cancer, they may reveal biochemical or metabolic abnormalities in the body that accompany cancer. For example, elevated levels of calcium or of the enzyme alkaline phosphatase may accompany cancer that is metastatic to the bones. Likewise, elevated levels of certain enzymes normally present within liver cells, including aspartate aminotransferase (AST or SGOT) and alanine aminotransferase (ALT or SGPT), signal liver damage, possibly through the presence of tumor metastatic to the liver. One current focus of research in the area of lung cancer is the development of a blood test to aid in the diagnosis of lung cancer. Researchers have preliminary data that has identified specific proteins, or biomarkers, that are in the blood and may signal that lung cancer is present in someone with a suspicious area seen on a chest X-ray or other imaging study.

Schematic illustration of a lung cancer located in the right upper lobe of the lung.