[Descriptive epidemiology of malignant neoplasm of the ovary in Japan]

Descriptive-epidemiological analysis of national mortality statistics on malignant neoplasm of the ovary revealed the following major findings. 1. Crude and age-adjusted mortality rates have gradually and constantly increased from 1947 to 1990 by 8.8 times and 5.4 times, respectively. 2. This increasing mortality trend was concluded to be mainly ascribable to the increasing rate of incidence rate and more accurate diagnosis. Eight background factors are generally considered to be determinants of the mortality trend. 3. Individual effects of age, year and birth cohort on mortality were analyzed and found to be constant after 50 years of age, uniformly increasing in 1950-1990, and clearly decreasing in cohorts born after 1931-1935. 4. A high standardized mortality ratio was detected in prefectures with large cities and in the northern part of Japan, with significant geographical clustering of the low standardized mortality ratio in the southern part, particularly in Kyushu Island. 5. The incidence rate of ovarian cancer was found to be relatively low in Japan as compared to the developed countries in Europe and the U.S.A..