[Estimation of cancer prevalence rates of selected sites in Japan, using the National Patient Survey data].

The prevalence rate and the one-day patient rate of cancer of selected sites in Japan are estimated from the data of National Patient Survey conducted by the Ministry of Health and Welfare for five years from 1976 to 1980. Observed cancer sites are esophagus (8th Revision of International Classification of Diseases, ICD; 150), stomach (ICD; 151), colon (ICD; 153), rectum (ICD; 154), liver (ICD; 155, 197.8), bile duct (ICD; 156), pancreas (ICD; 157), lung (ICD; 162), breast (ICD; 174), uterus (ICD; 180, 182.0, 182.9), prostate (ICD; 185), bladder (ICD;188) and ovary (ICD; 183.0). The one-day patient rate of stomach cancer is the highest among these sites, that is, 31.1per 100,000 population for males and 19.4 for females, followed by lung, breast and uterine cancers. Using the information on the intervals between visits, the prevalence rates of the patients including those treated on the exact day of the survey as well as those regularly visiting the medical facilities but not attended on the day were estimated. The prevalence rate thus estimated is the highest in the stomach, which is 101 in estimation 1 (including all outpatients) and 76 in estimation 2 (outpatients whose interval of visits is 31 days or more are excluded) per 100,000 population for males and, 77 and 47 for females respectively. The sites which show relatively high rates are as follows: breast (female); 79 and 33, uterine cervix (ICD; 180); 39 and 13 and unspecified uterus (ICD; 182.9); 55 and 19. The prevalence rates of breast and uterine cancer were relatively high when compared with both one-day patient rates and death rates. The age specific rates were also observed for the sites with rather high frequency in Japan such as the stomach, lung, breast and uterus. The prevalence rate of stomach cancer in females and uterine cancer showed a decreasing tendency with age from the 70s on. The prevalence rate of lung cancer tended to be lower than the mortality rate for all ages while the rates of other sites did not.