Seasonal Variation of Birth Incidence of Children with Cerebellar Medulloblastoma
A Study in Fukuoka-Ohita Area and in All Japan
1982 Volume 22 Issue 12 Pages 1002-1008
Details
1982 Volume 22 Issue 12 Pages 1002-1008
To explore the possibility that environmental factors may affect the incidence of childhood cancers, the monthly incidence of birth among cerebellar medulloblastoma patients was investigated. The data were collected from two series of investigations. One was the birth and residence data from the north-west district of Kyushu (Fukuoka-Ohita area, Japan) and the other was that of all Japan (from “Brain Tumor Registry in Japan”, 1981). Subjects in this study were children with verified cerebellar medulloblastoma who were at the age of five or under on admission. Twenty-one subjects residing in the Fukuoka-Ohita area were compared with 107 subjects from all Japan. The former group had been born during the period from 1955 to 1976; the latter was from 1969-1971 and 1974-1976. Control numbers of live births were calculated from the “Vital Statistics” of each area.
A tendency of seasonal accumulation of medulloblastoma patient births was seen in both groups in July, August, September, and October, with a peak value in September. The average number of medulloblastoma patient births per month and a monthly incidence rate per 100, 000-births were evaluated. It was evident that the births were significantly accumulated in August, September, and October (p < 0. 10). The monthly incidence rates of medulloblastoma patient births during these three months were twice as many as those in April, May, and June. The incidences of total live births revealed a high peak in January in both the Fukuoka-Ohita area and in all of Japan. The number of live births in June and November showed a dip in both groups.
In conclusion, the monthly incidence of cerebellar medulloblastoma patient births was higher in summer and autumn, especially in the months around September. Season-specific and concurrent etiological factors for cerebellar medulloblastoma and CNS anomalies may be present in and around the month of September.
