上海地区恶性肿瘤新发病例中,超过40%为消化系统恶性肿瘤[1],其中以胃癌和结直肠癌最为常见。胃癌是中国人群第2位常见的恶性肿瘤,占恶性肿瘤发病数的12.67%[2]。过去40年来,与世界多数国家一样,我国主要肿瘤登记点的胃癌年龄标化发病率都呈下降趋势[3],而结直肠癌已成为我国第3位常见的恶性肿瘤,占所有恶性肿瘤发病数的10.30%,主要肿瘤登记点的年龄标化结直肠癌的发 More than 40% of new cases of malignant tumors in Shanghai are digestive system malignancies [1], of which gastric and colorectal cancers are the most common. Gastric cancer is the second most common malignant tumor in Chinese population, accounting for 12.67% of the total number of malignant tumors [2]. Over the past 40 years, as in most countries in the world, the incidence of age-standardized gastric cancer has been on a decline in major cancer registration sites in China [3]. However, colorectal cancer has become the third most common malignancy in China and accounts for all malignant tumors 10.30% of the numbers, the age-standardized colorectal cancer of the major tumor registration points