胃癌发病因素复杂,发病过程较长,其病因尚未阐明。然而,目前已经认识了一些发病因素,它们对预防胃癌发病有重要意义。流行病学调查表明,世界不同地区的胃癌发病率相差悬殊,日本和智利最高,澳洲和美国仅为前者的五分之一。国内情况相仿,西北各省至东部沿海形成一条高发带,而西南及两湖、两广最低。即便上海一市,普陀、闸北及杨浦区明显高于静安、徐汇及虹口区。此外,移民流行病学研究发现,美国加州及夏威夷的日本移民的胃癌发病率呈渐降趋势。第一代 The pathogenesis of gastric cancer is complex, the course of the disease is longer, the etiology has not been elucidated. However, some of the pathogens have been recognized so far, and they are of great importance in preventing the onset of gastric cancer. Epidemiological survey shows that the incidence of gastric cancer in different regions of the world disparity, Japan and Chile highest, Australia and the United States only one-fifth of the former. The situation in China is similar to that of the provinces in the northwestern provinces and the eastern coasts, and the lowest in Guangdong and Guangxi provinces. Even in Shanghai, Putuo, Zhabei and Yangpu districts were significantly higher than Jing’an, Xuhui and Hongkou districts. In addition, immigration epidemiological studies found that the incidence of gastric cancer in Japanese immigrants in California and Hawaii in the United States showed a decreasing trend. First generation