What causes brain and nervous system tumors is not entirely clear. Some epidemiologic studies have suggested that an increased risk of certain nervous system tumors is associated with high-dose radiation treatment, especially among patients who received treatment as children. Other studies have suggested that atomic bomb radiation exposure is associated with an increased risk of certain nervous system tumors.
To measure the impact of radiation exposure on the incidence of nervous system tumors, Dale L. Preston, Ph.D., of the Radiation Effects Research Foundation in Hiroshima, Japan, and his colleagues used information from tumor registries, medical records, and death certificates to identify benign and malignant tumors of the primary nervous system and pituitary gland that were diagnosed between 1958 and 1995 in 80,160 Japanese atomic bomb survivors. Study pathologists reviewed the records to confirm the diagnoses.
The authors found that radiation exposure was associated with an increased risk of all nervous system tumors combined. This risk was particularly high for schwannomas, a benign tumor of the nervous system. Further analysis revealed that men had a higher risk of nervous system tumors than women, and people exposed to radiation as children had a higher risk than those exposed as adults.
Although additional follow-up is needed, the authors say their findings "demonstrate that radiation exposure can increase the risk of nervous system tumors and suggest that these increased risks persist throughout lifetime, regardless of the age at exposure."
Contact: Dale Preston, Radiation Effects Research Foundation, 81-82-261-7219 (8 p.m. to 4 a.m. EDT), 81-82-242-6041 (6 a.m. to 11 a.m. EDT), firstname.lastname@example.org
Preston D, Ron E, Yonehara S, Kobuke T, Fujii H, Kishikawa M, et al. Tumors of the nervous system and pituitary gland associated with atomic bomb radiation exposure. J Natl Cancer Inst 2002;94:1555-63.
Note: The Journal of the National Cancer Institute is published by Oxford University Press and is not affiliated with the National Cancer Institute. Attribution to the Journal of the National Cancer Institute is requested in all news coverage.