Trends in cancer mortality, incidence and survival in Japan.

Cancer has been the leading cause of deaths since 1981 in Japan and is still on the increase accounting for 27% of all causes of deaths in 1989. The crude death rate of cancer has been increasing in both sexes, but the age-adjusted death rate has been stable in males and decreasing in females. Among various cancers cancers of the stomach, uterus, liver (females only), and esophagus (females only) have been decreasing. Leukemia and bladder cancer also tend to show a declining trend. Other cancers, especially cancers of the lung, colo-rectum, pancreas, biliary tract liver (males only), prostate, ovary, and breast are increasing in Japan. Trends in the cancer incidence are similar to those of cancer mortality. Causes of the marked secular trends in the cancer mortality and incidence are not clear, but the major causes are suspected to be changes in dietary habits, smoking and drinking habits, and other socio-environmental factors such as marital and reproductive factors. The five year survival rates of several cancers have been improved in the last decades. Thus, progresses in the diagnostic and therapeutic techniques and promotion of cancer screening may have also contributed to the decrease of cancer deaths. If the present trends in cancer mortality and incidence continue, cancer deaths/incidences will still increase and cancers of the lung, colo-rectum, liver (males only), pancreas, biliary tract, etc. will become major cancers in Japan in the future. To combat with ever increasing cancer it is necessary to further promote cancer research, cancer screening, programs for primary prevention of cancer, especially smoking control and improvement of dietary habits.