[Risk factors of gastric cancer in Wuwei City---an endemic region of gastric cancer].

Background & Objective: Researches show that epidemiologic factors of gastric cancer include living habit, eating moldy food and pickles, dystrophy, lack of microelements, and inherit, etc. This study was to explore universalities of these factors in Wuwei, a city in northwest China with high incidence of gastric cancer, and provide evidences for the first-prevention of gastric cancer.

Methods: Family histories of the residents in Wuwei City were investigated with case-control method. Separating ratio and heredity degree of gastric cancer were calculated with Li-Mantel-Cart method and Falconer's regression method. Chronic gastritis patients were followed-up by home-visit, gastroscopy, and pathology. Cancerigenic fungi and volatility N-nitrosate compounds in residents' meal, Helicobacter pylori (Hp) in gastric mucosa, and total content of vitamin C in 293 healthy adults' serum were detected by culture, authentication, and laboratory examinations.

Results: In Wuwei City, the separating ratio of gastric cancer was 0.077; the heredity degree of first-degree relatives was 22.91%u cancerization rate of year in person of atrophic gastritis crowd was 1.09%. Eight kinds of nitrosamine and 14 kinds of cancerigenic fungi were detected from residents' meal. Total content of vitamin C in serum of the 293 healthy adults in summer was (5.74+2.79) mg/L. Positive rate of Hp in gastric mucosa of the residents was 67%.

Conclusion: The major extrinsic factors of gastric cancer in Wuwei City include various strong carcinogens existing in residents' meal and lack of vitamin Cu its intrinsic factors include infection of Hp, atrophic gastritis (especially atypical hyperplasia), and heritage susceptibility.