Incidence
In 1998, cancer among children will compromise 3.7% of all cancer among males and 2.6% of all female cancer. There will be around 2,707 new cases, 1,536 cases in boys and 1,171 among girls. Leukemias are the most common, compromising 47.8% of cancers among boys and 48.0% among girls. There will be around 735 new leukemia cases among boys and 563 new cases among girls. Other sites include brain and nervous system, retina, lymph nodes, kidney, bone and soft tissues, gonadal and germ cell sites.
Early detection
Malignancies in children are difficult to detect because they may present similarly as other common childhood diseases. Parent should have their children undergo regular medical check-up and be alerted to the following symptoms which may be associated with cancer in children: prolonged, unexplained fever or illness; unexplained pallor; increased tendency to bruise, unexplained localized pain or limping; unusual masses or swelling; frequent headaches, often with vomiting; sudden eye or visual changes; sudden or progressive weight loss.
Some of the main childhood cancers are:
Leukemias: The most common, compromising 47.8% of all childhood cancers. Leukemias may either be acute (with uncontrolled proliferation of immature or “ blastic” cells) or chronic (proliferation of the more mature or differentiated cells). Leukemias may vary in presentation. Some are detected on routine physical examinations. Some, however, present with pallor, easy bruisability, malaise, anorexia, intermittent fever, bone pains, abdominal pain or bleeding.
Brain and spinal cancer: These rank 2nd, compromising 9.7% of all cancers. In the early stages of brain tumors these may cause headaches, dizziness, (often with nausea or vomiting), blurring of vision, double vision, difficulty in walking or handling of objects.
Lymphomas (Hodgkin’s Disease or non-hodgin Lymphoma): These rank 3rd, compromising 9.0% of all cancers. These usually involve the lymph nodes but may at times arise from other organs rich in lymphoid tissue. They cause swelling of lymph nodes in the neck, chest axilla and groin. They may also present as generalized weakness and fever.
Retinoblastoma: This ranks 4th, compromising 7.5% of all cancers. This is an eye cancer which usually occurs in children below four years old. The more common presenting signs include the cat’s eye reflex (a whitish appearance of the pupil) or squint. A red and painful eye, limitation of vision or proptosis are noted in the late stages.
Wilm’s tumor: This is a cancer of the kidney occurring in very young children. Usual presentation is an abdominal or flank mass. It compromises 3.4% of all childhood cancers.
Osteogenic sarcoma: A type of bone cancer which usually presents with pain, with or without swelling or a mass overlying the involved bone. It compromises 2.3% of all cancers in children.
Rhabdomyosarcoma: This is the most common soft tissue cancer in children, often presenting as a mass which may be painful. It usually occurs in the following sites: head and neck, genito-urinary tract, trunk, and extremities. It compromises 2.2% of all childhood cancers.
Gonadal and germ cell sites: These usually present as a testicular mass, or a pelvic mass among girls. They are 9th most common diagnostic group, compromising 3.6% of all cancers in children.
Treatment
Management of childhood cancers is usually by a combination of the different modalities of treatment (surgery, radiotherapy, chemotherapy), coordinated by a team of experts including pediatric oncologists, surgeons, nurses, social workers, psychologists and others who assist children and their families.
Survival
5-years survival rates markedly vary according to the sites of origin of the tumor.