Ecological Study Of The Mortality Of Colorectal Cancer During Different Periods After Schistosomiasis Was Primarily Eliminated

Objective To study the longtime tendency of the mortality of colorectal cancer after schistosomiasis was primarily eliminated and explore whether schistosomiasis may cause colorectal cancer. Method based on the death data of colorectal cancer from Kunshan city(severely epidemic area of schistosomiasis) and Zhangjiagang city (non-epidemic area of schistosomiasis) during 1973-1975,1981-1983,1990-1992 and 2001-2003, the study of ecological comparison and ecological tendency was conducted. Result Although in male and femal the mortality and standardized mortalityof colorectal cancer in Kunshan city was higher than that in Zhangjiagang city during the four periods, this tendency weakened with time (ratio of standardized mortality),from 1973-1975 (2.36) to 2001-2003 (1.31) in male, from 1973-1975 (2.94) to 2001-2003 (1.54) in female. The study of ecological tendency suggested, although the mortality of colorectal cancr persistently rose in Zhangjiagang city, it had not been seen in Kunshan city during the four periods. Although in male and female the age-specific mortality of colorectal cancer in Kunshan city was higher than that in Zhangjiagang city during 1973-1975 and 1981-1983, the mortality of high age groups significantly rose in Zhangjiagang city during 1990-1992 and 2001-2003, and near or pass the level in Kunshan city in some age groups. Although the average death age of colorectal cancer in Zhangjiagang city was...