Incidence of intracranial meningiomas in Nagasaki atomic-bomb survivors.

Among the Nagasaki atomic-bomb survivors registered at the Scientific Data Center for Atomic-Bomb Disaster, Nagasaki University School of Medicine, 45 cases of surgically treated intracranial meningioma were collected from 6 hospitals with departments of neurosurgery in or near Nagasaki City during the period from 1973 to 1992. All 45 patients were over 40 years of age at the time of diagnosis. Subsequently, the 45 cases were statistically analyzed in relationship to the estimated distance from the hypocenter by age, gender, intracranial location, histology and latent period. The analysis showed a high correlation between incidence of meningiomas and distance from the hypocenter. The incidence among Nagasaki atomic-bomb survivors over 40 years of age, especially in those proximally exposed, appears to be increasing, in inverse proportion to the exposure distance, since 1981, 36 years after the explosion of the atomic bomb.