Decline of stomach cancer mortality rates in a high-risk geographical area.

An investigation on gastric cancer death rates per 100,000 population, by sex and age groups in Chile, covering a 34-year period (1941-1974), was made. The yearly change in gastric cancer mortality rates, calculated by linear regression analysis, for males 25-34 years of age (-0.043), P less than 0.00005), 35-44 (-0.381, P less than 0.00005), 45-54 (-1.340, P less than 0.00005), 55-64 (-2.080, P less than 0.00005), 65-74 (-0.602, N.S.), and age-adjusted death rates for persons aged 25-74 years (-0.959, P less than 0.0006) showed negative regression coefficients. The yearly change in gastric cancer death rates for females 25-34 years of age (-0.051, P less than 0.00005), 35-44 (-0.468, P less than 0.00005), 45-54 (-1.430, P less than 0.00005), 55-64 (-2.978 P less than 0.00005), 65-74 (-1.841, P less than 0.00005), and age-adjusted rates for persons aged 25-74 years (-0.991, P less than 0.00005) also exhibited negative regression coefficients, all being statistically highly significant.