Childhood Cancer Survivors Treated With Radiation Face Increased Risk Of Tumors Later In Life

The risk of secondary cancers occurring in childhood cancer survivors varies depending on the original cancer, age of the survivor at the first cancer diagnosis, and the primary treatment given, said Joseph Neglia, M.D., pediatric oncologist and researcher with the University of Minnesota Medical School and Cancer Center. He was the lead researcher on this study.

"Secondary tumors of the central nervous system can have particularly devastating consequences and have been linked to earlier treatments for childhood leukemia and brain tumors," he said.

Neglia and his colleagues reviewed information from the more than 14,300 five-year survivors of childhood cancer who are participating in the University's Childhood Cancer Survivor Study. The researchers also obtained information about the survivors' exposure to radiation and the chemotherapy used to treat the first cancer.

They found that 116 of the survivors developed subsequent tumors of the brain and central nervous system. Radiation treatment for childhood cancer was linked to a higher risk for developing malignant brain tumors like glioma, and benign tumors like meningiomas later in life. The risk of a second tumor increased as the dose of radiation used to treat the first cancer increased.

"Children under age 5 were especially vulnerable to the development of secondary brain tumors," says Neglia. "We think the increased tumor incidence may mean that the developing brain of a young child is very susceptible to the effects of radiation."

The researchers noted that "prolonged follow-up of all childhood cancer survivors, particularly those exposed to radiation, is crucial to the early detection of these tumors and should be considered part of the effective therapy of the primary disease."

Neglia added, "All people treated for cancer as children should be in a long-term follow-up clinic where a physician can review their individual treatment, discuss the health issues they may encounter later in life, and recommend the necessary screenings."

Researchers working with Neglia on this study included Leslie Robison, Marilyn Stovall, Yan Liu, Roger Packer, Sue Hammond, Yutaka Yasui, Catherine Kasper, Ann Mertens, Sarah Donaldson, Anna Meadows, and Peter Inskip. The study was funded by the National Cancer Institute and the Children's Cancer Research Fund (CCRF). For more information about childhood cancer and the Childhood Cancer Survivor Study, visit http://www.cancer.umn.edu/ccss.