Primary malignant nervous system neoplasms. Birth cohort effect in the elderly
N. E. Bharucha, R. H. Raven and B. S. Schoenberg
Current data indicate that mortality for primary malignant nervous system
neoplasms (NSNs) provides a fairly accurate index of incidence. Average
annual age- and sex-specific death rates among whites for primary malignant
NSNs in the 48 contiguous United States from 1940 through 1975 showed a
marked cohort effect among the elderly of either sex. For white men aged 60
through 64 years, mortality increased steadily from 5.3 per 100,000 per
year for those born in 1880 to 16.1 per 100,000 per year for the 1910
cohort. No definite cohort effect was seen in the young. The increase in
mortality could be due to better diagnosis and more complete case
ascertainment for deaths due to primary malignant NSNs, but further studies
are required to distinguish a real from an artifactual increase in
mortality.