甘肃省武威市胃癌危险因素分析

Study on risk factors of gastric cancer in Wuwei city of Gansu province

目的分析甘肃省武威市胃癌高发的危险因素，为胃癌的一级预防提供病因学线索。方法应用移民流行病学研究方法对移居新疆维吾尔自治区奇台县的武威籍居民因胃癌死亡的情况进行调查；地区聚集性分析根据胃癌死亡登记资料采用Poisson分布模型拟合，并用频数分布拟合优度的X^2检验进行验证；家族聚集性分析，采用二项分布（p＋q）^n数学模型拟合，实际发病数与理论数的差异比较用X^2检验；用历史性队列研究方法观察四种癌前疾病的癌变情况；采用紫外分光光度法和盐酸萘乙二胺法分别测定饮用水中的硝酸盐氮和亚硝酸盐氮含量。结果移民胃癌一代及后裔均较祖籍武威市同期的死亡率为低，但高于定居地奇台县同期死亡率水平；胃癌在以村为单位和家族中呈现地区和家族聚集性；胃息肉、萎缩性胃炎、胃溃疡、残胃等四种癌前疾病的人年癌变率依次为0．459％、0．431％、0．381％、0．178％；人群特异危险度百分比依次为41．26％、29．35％、4．68％、3．39％；硝酸盐氮和亚硝酸盐氮无论是地表水还是浅井水武威市均明显高于兰州市（P〈0．01）。结论移民一代及后裔的胃癌死亡率低于祖籍但高于定居地的水平，胃癌发病存在地区与家族聚集性；居民饮用水中富含硝酸盐氮和亚硝酸盐氮；胃息肉、萎缩性胃炎、胃溃疡、残胃等四种胃部慢性疾病为武威市胃癌高发的内在因素。

Objective The incidence of gastric carcinoma（GC） has significantly difference in different areas because it has different cancerogenic and stimulative factors in different areas. Through displaying the epidemic factors of popular GC in Wuwei city, it can supply etiological clue of the first-level prevention to GC. Methods The research methods about epidemiology of migrant were used to investigate the case fatality rate of GC about the people in Qitai county of Xinjiang province who immigrated from Wuwei. According to the information of GC-death registered, we fitted local cluster analyse with Possion-distribution model, and then the results were processed with case-control study of chi square test; Binomial distribution （p＋q）^n model was used to familial cluster analysis, and the statistical method of X 2 was used to compare the difference between the actual incidence and theoretical incidence of GC. Adopting the history arrangement analysis , the canceration of four precancerous diseases were observed. Nitrogen content of nitrate and nitrite in drinking water were respectively measured by using ultraviolet spectrophotometric and hydrochloride naphthaline ethylenediamine methods. Results The death rates of GC of the first-generation and their descendants of emigrants were much lower than those contemporary beings in Wuwei, but were higher than those contemporary beings in Qitai country. The prevalence of＇GC had region and familial aggregation. The year canceration proportion of people who had precancerous diseases such as stomach polypus, atrophyic gastritis, gastric ulcer, and remnant stomach were 0.459 %, 0.431%, 0.381% and 0.178 % respectively. The percentage of crowd attributive risk were 41.26 %, 29.35 %, 4.68 % and 3.39 % respectively. Nitrogen contents of nitrate and nitrite either in surface water or in shallow water were significantly higher in Wuwei city than that in Lanzhou city （P 〈0.01）. Conclusion Death rates of GC for the emigrants of the firstgeneration and their descendants are much lower than their ancestry, but higher than those of the generation in Qitai county. The prevalence of GC has region and familial aggregation. It is the immanent factor of popular GC in Wuwei City that there are higher contents of nitrogen content of nitrate and nitrite in residenter＇s drinking water and four precancerous diseases including stomach polypus, atrophyic gastritis, gastric ulcer, and remnant stomach.