Longitudinal Gompertzian analysis of mortality from stomach cancer in Japan, 1950–1993

Abstract

Age-specific mortality rates from stomach cancer (SC) in Japan from 1950 through 1993 were subjected to longitudinal Gompertzian analysis. Age-specific SC mortality rate distributions between ages 45 and 75 years were highly Gompertzian for each- and every year for both men and women. Between 1950 and 1993, age-adjusted SC mortality rates decreased 48.6% for men and 59.6% for women. Gompertzian analysis might suggest that declining SC mortality rates can be attributed to beneficial environmental influences during that period, especially after 1970. This suggests that the environmental factor has changed to account for the dramatic decline in the incidence of, and mortality from SC. The environment was 32.3 and 14.4 times less conducive to mortality from SC in 1993 as compared to 1950 for men and women respectively. Reduced salt consumption was considered as the decline in the SC mortality rate. Intake of green-yellow vegetables, fruits, and vitamin A were also considered as factors for reducing SC mortality. The mass-screening for SC may effectively enhance survival for SC patients, which might partially contribute to a dramatic decline in SC mortality.