From a statistical point, we understand that cancers in children may be related to genetic defects, chromosomal aberrations, immune deficiencies, infections like Epstein-Barr virus, Hepatitis B virus and human immunodeficiency virus infections, radiation mishaps, immunosuppressive treatments, or even anticancer treatments.
On the other hand, there is NO or insufficient evidence to associate the following with cancers in children: mother's diet during pregnancy, vitamin K injection given to the newborn infant, vaccinations, electromagnetic field, or power lines near residence.
Types of cancer
Acute Lymphoblastic Leukaemia (ALL). This is the commonest type of cancer seen in children. Almost 30% of childhood cancers are ALL. The affected child may have fever, bruises, tiring easily, and enlargement of the glands in the neck. Most children with ALL need chemotherapy only; some may require radiation treatment to the brain. On the whole, 75-80% of children can be cured after treatment.Acute Myeloid Leukaemia (AML). This is an uncommon form of leukaemia. The affected child has symptoms that are similar to those of acute lymphoblastic leukaemia. Most children with AML need chemotherapy only. On the whole, 45-60% of children can be cured after treatment.
Non-Hodgkin Lymphoma (NHL). This is a cancer of the lymphatic glands. The affected child may have fever, tiring easily, and enlargement of the glands in the neck or inside the chest. Some children may complain of difficulty in breathing or abdominal pain. On the whole, over 80% of children can be cured with chemotherapy alone. Only a small proportion of children will need surgery or radiation treatment.
Hodgkin Lymphoma. This is another form of cancer of the lymphatic glands and the symptoms are similar to those of non-Hodgkin Lymphoma. Treatment with chemotherapy, and radiation in some children, results in cure rates of over 80% even in advanced disease.
Brain Tumours. Brain Tumours are the commonest form of solid cancer in children, accounting for 15-20% of the cases. There are different kinds of brain tumours in children and their treatments are not the same. Children with brain tumours may complain of headache, vision problems, vomiting, weakness of one side of the body, unsteadiness in walking, or epilepsy. In general, the affected children will need surgery and often radiation treatment afterwards. Medulloblastomas, a tumour commonly seen in the cerebellum of children, is treated with surgery, radiation and chemotherapy. The chance of cure is 60-70% when the tumour has not spread.
Germ cell tumours inside the brain (intracranial) are more commonly seen in Oriental children. They are peculiar because most of them can be treated with chemotherapy and radiation without the need for complicated surgery. The cure rates range from 60-90% depending on the type of germ cell tumour.
Neuroblastoma. This is a cancer of the adrenal glands inside the abdomen. Occasionally they are found in the nervous tissues inside the neck or the chest. The affected child may have fever, aches in the bones, and distended abdomen. For early disease, the outcome is excellent and more than 90% of the children can be cured. Unfortunately, most children present with advanced disease with spread to other parts of the body. Treatment with surgery, chemotherapy and sometimes radiation is needed. High-dose chemotherapy followed by stem cell transplantation is now part of the standard treatment. Only 10-30% of children can survive long-term.
Wilms Tumour. This is a cancer of the kidneys and most of the affected children present with distention of the abdomen. The standard treatment consists of surgery, chemotherapy and radiation. The outcome is excellent with 80-90% of cure even in advanced disease.
Germ Cell Tumours. This is a cancer of the testis in boys or the ovaries in girls. Sometimes they may occur inside the abdomen, the chest, the neck or at the coccyx near the anus. Some patients may need surgery alone, while others can be treated with only chemotherapy. The cure rates ranged from 75-90% even with advanced diseases.
Rhabdomyosarcoma. This is a cancer of the muscles and it commonly presents as a mass. Any part of the body may be affected. Treatment consists of surgery, chemotherapy and radiation. The long-term cure rates ranged from 70-80% when the disease has not spread.
Osteosarcoma (or Osteogenic Sarcoma). This is a cancer of the bones and commonly present as a swelling in the thigh or leg bones. Treatment consists of surgery and chemotherapy. About 60-70% of children can survive long-term after treatment when the cancer has not spread.
Ewing Sarcoma (or Primitive Neuroectodermal Tumour). This is a cancer of the nervous system that may affect the bones or the soft tissues. The symptoms are therefore similar to those of Rhabdomyosarcoma or Osteosarcoma. Treatment consists of surgery, chemotherapy and radiation. For disease that has not spread, the long-term survival rates are 70-80%.
Hepatoblastoma. This is a cancer of the liver. The affected child usually presents with a distended abdomen. With surgery and chemotherapy, the long-term survival rates are close to 90% for disease that has not spread.
Retinoblastoma. This is a cancer of the eyeball. During the early stage, parents may notice a white reflex (cat's eye reflex) in the affected eye, especially when the child's face is photographed. In early stages, the cancer can be treated by surgery or cryosurgery. For more advanced disease, radiation treatment and chemotherapy may be needed. Long-term survival rates are well above 90% unless the disease has spread beyond the eyeball.