Abstract
In recent years, with the changing pattern of cancer death rates among various sites, and the introduction of more effective medical treatments, estimates of future trends of cancer from current death rates are somewhat misleading. Therefore, it is important for policy makers to obtain information on incidence rates when establishing countermeasures against cancers. The Nagasaki Cancer Registry Program was established in 1963 and provides quite accurate data with histologic information. Therefore, in this study, incidence rates of cancer for 2010 were estimated with a linear regression model and the Nagasaki Cancer Registry data from 1985 through 1991. It was estimated that the number of male cancer patients will increase from 3, 373 in 1990 to 5, 624 in 2010 (67% increase) and that of female cancer patients from 2, 734 in 1990 to 4, 426 in 2010 (62% increase) . In both males and females colon cancer is the most common type, followed by stomach cancer; breast cancer is third most common in females. Although incidence rates for stomach cancer are decreasing, because of the aging Japanese population, stomach cancer will remain a major problem in the near future. Discrepancies between the regression coefficient of incidence rates and death rates were found for stomach, colon, and breast cancers. In particular, death rates from breast cancer showed little change in each age group, but incidence rates showed a steep increase in most age groups. Therefore, it is important to analyze incidence rates rather than death rates to determine future trends and to establish effective countermeasures against cancers.
