结肠癌为最常见恶性肿瘤之一，特别是在欧美国家其发病率相当高，结肠癌在美国男女癌症病人中均占第二位，男性仅次于肺癌，女性仅次于乳腺癌（1）。在我国，结肠癌的发病率呈上升趋势，尤其在一些发展较快的城市和地区，如上海地区胃肠道恶性肿瘤发病率居首位的为胃癌，其次即 Colon cancer is one of the most common malignancies, especially in Europe and the United States. Incidence of colon cancer is the second highest among men and women in the United States. Men are second only to lung cancer, and women are second only to breast cancer (1). . In China, the incidence of colon cancer is on an upward trend, especially in some fast-growing cities and regions. For example, in Shanghai, the incidence of gastrointestinal cancer is ranked first in gastric cancer, followed by