Preliminary study of meningioma incidence in Nagasaki atomic bomb survivors

Twenty six A-bomb survivors with meningioma were analyzed to examine the correlation between A-bombing radiation and the incidence of meningioma. According to exposure distance, 9 had been exposed at <2,000 m from the hypocenter and the remaining 17 exposed at ≥2,000 m. The incidence of meningioma was determined from the surgery rate, because surgery is the treatment of choice in this disease. There was a high correlation between the surgery rate of meningioma and exposure distance; and the rate of surgery was significantly higher in the <2,000 m exposed group than the ≥2,000 m exposed group in both men and women. The surgery rate tended to be increased with year, especially in the <2,000 m exposed group. It seems that the age at surgery, occurrence site, and histology type among patients in the exposed group are not different when compared with those in 76 non-exposed patients. (N.K.)