The epidemiology of malignant neoplasms of the stomach in Canada during the period 1931-1984.

Morbidity patterns in Canada for malignant neoplasms of the stomach were examined for the period 1970-1980 and mortality patterns for the period 1931-1984. Age-standardized morbidity rates (ASMR) have declined significantly in males (p = 0.011) and females (p = 0.0011) during the period studied by, on average, 0.20 fewer new cases per 100,000 population per yr. The significant declines in ASMRs are attributable to significant declines in age-specific rates for males aged 35-44 (p = 0.013) and 55-64 (p = 0.046) and females aged 55-64, 65-74, and 75-84 yr (p less than 0.015). Significant declines in age-standardized death rates (ASDR) have also occurred in both males and females (p = 0.0001), with 15 of the 16 age-sex groups studied showing significant rates of decline (p less than 0.0005). The greatest rates of decline were noted for males and females aged 75-84, where age-specific rates have declined by more than 4.2 deaths per 100,000 population per yr since 1931.