BACKGROUND: Several studies have proved that uterine cancer mortality has decreased in Japan over the past 50 years, but the age demographics in this regard are not clear. This study investigated the change pattern of age characteristics for this cancer. METHODS: Cause-specific mortality was identified in the population of Japan and Ireland in the years 1950-2000. Time trends of age-specific mortality rate were assessed by fitting linear regression. The change rates between 1950 and 2000 were calculated in comparison with Ireland. The contribution of death from uterine cancer was estimated using cause-elimination life tables. RESULTS: The mortality rate of uterine cancer decreased 59% from 1950 (19.7 per 100,000 women) to 2000 (8.14 per 100,000 women). Age-specific rates for women younger than 70 decreased around 80%, whereas that for women over 85 increased 105% during the same period. Correspondingly, the age of 70 years was the median age for the negative contribution of uterine cancer to life expectancy. Younger than that age, the trend of negative contribution decreased, over that age, it was increased. CONCLUSIONS: Mortality from uterine cancer tended toward the aging in Japan. The general mortality reduction trend was attributed to younger people and adults. These age characteristics can be explained by the increase in life expectancy during the 50-year period.
BACKGROUND: Several studies have proved that uterine cancer mortality has decreased in Japan over the past 50 years, but the age demographics in this regard are not clear. This study investigated the change pattern of age characteristics for this cancer. METHODS: Cause-specific mortality was identified in the population of Japan and Ireland in the years 1950-2000. Time trends of age-specific mortality rate were assessed by fitting linear regression. The change rates between 1950 and 2000 were calculated in comparison with Ireland. The contribution of death from uterine cancer was estimated using cause-elimination life tables. RESULTS: The mortality rate of uterine cancer decreased 59% from 1950 (19.7 per 100,000 women) to 2000 (8.14 per 100,000 women). Age-specific rates for women younger than 70 decreased around 80%, whereas that for women over 85 increased 105% during the same period. Correspondingly, the age of 70 years was the median age for the negative contribution of uterine cancer to life expectancy. Younger than that age, the trend of negative contribution decreased, over that age, it was increased. CONCLUSIONS: Mortality from uterine cancer tended toward the aging in Japan. The general mortality reduction trend was attributed to younger people and adults. These age characteristics can be explained by the increase in life expectancy during the 50-year period.