[Cancer incidence in Japan].

Based on the estimates by the Research Group for Population-based Cancer Registration in Japan, time-trend of cancer incidence in Japan was described and analyzed. During the period of 1975-1998, the annual total cancer incidence increased 111,000-290,000 in males, and 96,000-208,000 among females. The higher incidence was prominent for cancers of the colorectum, lung, liver, gallbladder and extrahepatic bill duct (both sexes), prostate, and breast (female), whereas it was low or negligible for cancers of the stomach (both sexes) and uterus. The increased cancer incidence was globally attributed to the rapid growth of the Japanese aged population. However, a remarkable increase in the age-standardized incidence rate was also observed for cancers of the colorectum (both sexes), prostate, and breast (female). A decline in the age-standardized incidence rate was continuously observed for cancer of the stomach and uterus. A birth cohort analysis has revealed that the cancer incidence in Japan has been highly affected by the generation. Based on the Cancer Incidence in Five Continents Vol. VIII, the cumulative risk of cancer incidence (0-79 years old) was calculated and compared among the Japanese population (6 registries' data), US-Japanese and US-white. Several characteristics were suggested and discussed for Japanese cancer risk.