Malignant Childhood Neoplasm

Definition

Childhood cancers are malignant diseases that affect children under the age of 18 years.

Description

Cancer in children (pediatric cancers) differs from cancer in adults in several important ways. The most important difference is that children have generally better prognoses than do adults. Two-thirds of children with cancer are cured of the disease. Still, despite enormous progress in the treatment of childhood cancer since the 1960s, it is the second-most common cause of death in children older than one year, with accidents being the first.

One difference between pediatric and adult cancer is found in the cells in which the cancers originate. Many adult cancers begin in specific organs, such as a lung, the breast, or the colon. Childhood cancer, except for leukemias and brain tumors, often arise in connective tissues such as bone and muscle.

Childhood cancer is often more aggressive than adult cancers. It grows faster and is frequently metastatic (has moved to other parts of the body or to the major organs) by the time of diagnosis. Thus, surgery alone is less likely to cure a child. Nevertheless, the cancers children develop tend to be more responsive to chemotherapy and radiation than those of adults.

The median age for children at the time of a cancer diagnosis is six years; for adults it is 67 years. Most children with cancer are otherwise healthy; many adults have conditions, such as heart disease, that make their treatment and recovery more difficult. Another important difference is that screening tests are available for some adult cancers, such as mammograms for breast cancer and Pap smears for cervical cancer. There are no useful screening tests for childhood cancers. Not infrequently, the diagnosis is made at a routine pediatric visit.

An extremely important factor in the improved prognosis of children with cancer has been the enrollment of the majority of children with cancer in research trials. Although only 2% of all cancers diagnosed in the United States occur in children, more than 70 percent of those children are enrolled in formal research protocols. By contrast, although adults have 98% of all cancers diagnosed in the United States, only 3% enroll in trials. Research protocols permit rapid collection of data on the effectiveness of treatment; they recognize adverse effects quickly, and foster valuable communication and collaboration among pediatric oncologists throughout the country and the world. In 1998, the four major pediatric research consortia in the United States joined forces. The Pediatric Oncology Group, the Children's Cancer Group, the Intergroup Rhabdomyosarcoma Study Group, and the National Wilms' Tumor Study Group, combined to form the Children's Oncology Group—to the great benefit of children with cancer.

Demographics

About 8, 700 cases of cancer are diagnosed in children under the age of 15 years in the United States each year. Another 2, 000-3, 000 are diagnosed in teenagers over 15 years of age, but these are often recorded with adult diagnoses. The number of cases of childhood cancer has remained steady for a number of years. Researchers estimate that 1 of every 333 children will be diagnosed with cancer before the age of 20 years.

Leukemia accounts for 31% of the cancers in children, with about three-quarters of those being acute lymphoblastic leukemia and the other one-fourth mostly acute myelocytic leukemia. Central nervous system (CNS) cancers, commonly lumped together as brain tumors, are the next largest group, constituting another 17%. Lymphoma, both Hodgkin's and non-Hodgkin's, accounts for 15 percent of childhood cancers. The rest of the diagnoses are divided among what are referred to as solid tumors, such as neuroblastoma, retinoblastoma, Wilms' tumor, rhabdomyosarcoma, and bone cancers.

These statistics are similar in other parts of the developed world. In Africa, the most common form of childhood cancer is Burkitt's lymphoma, which is associated with the Epstein-Barr viral infection.

The survival rate for children with cancer is approaching 80% in the United States.

Content
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Author Info: Marianne Vahey M.D., The Gale Group Inc., Gale, Detroit, Gale Encyclopedia of Cancer, 2002

This feature is for informational purposes only and should not be used to replace the care and information received from your healthcare provider. Please consult a healthcare professional with any health concerns you may have.