title: The age curve of nervous system tumour incidence in adults: common shape but changing levels by sex, race and geographical location.
abstract: A multiplicative model was fitted to incidence rates of nervous system tumours cross-tabulated for each sex by five-year age groups between ages 35-64 and 51 populations in which at least ten cases had been observed and 60% of cases histologically verified. There was no significant departure from a model in which the age curve was assumed to have the same shape but a different level in each population. On log-log scale this shape was a straight line with identical slope (2.6) for males and females. Population-specific multipliers were highest in Israel and lowest in Asia. Within the US, rates were significantly lower among blacks, Hispanics, Chinese and Japanese compared to whites. A model for both sexes combined showed that sex ratios were rarely below unity but varied significantly between populations. Exposure (or susceptibility) to as yet unidentified aetiological factors appears to be higher in males and whites than in females and non-whites.
mesh_terms: D000328:Adult; D000367:Age Factors; D000569:Americas; D001208:Asia; D001315:Australia; D005060:Europe; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009423:Nervous System Neoplasms / Q000453:epidemiology* / Q000208:ethnology; D012737:Sex Factors; D013223:Statistics as Topic