结直肠癌是常见的恶性肿瘤,在世界范围内其死亡率居各种肿瘤的第三位,在西方居第二位。在我国随着生活水平的提高,饮食习惯的改变,总体发病率呈上升趋势,据调查2000年至2005年间发病人数增加了12万,男性增加了19·1%,女性增加了17·7%。其发病的机制一般认为有两种类型:一种是 Colorectal cancer is a common malignancy, its mortality rate ranks the third in all kinds of tumors in the world, ranking second in the west. In our country, with the improvement of living standards and eating habits, the overall incidence is on the rise. According to the survey, the number of cases increased by 120,000 between 2000 and 2005, with men increasing by 19.1% and women by 17.7% . The pathogenesis of the general view that there are two types: one is