[Multiple stepwise regression analysis of etiological factors of esophageal cancer in Cixian county].

Cixian county, one of the high-risk counties of esophageal cancer in the world, has a standardized mortality of 142.19/10(5) population, 1969-1971. The incidence of esophageal cancer had dropped year by year from 1974 to 1982. The significance of the incidence tendency was studied. The results are highly significant (P less than 0.001). The causative factors of esophageal cancer including five independent variables: X1 (number of people taking sanitized water), X2 (number of people on pickled Chinese cabbage), X3 (annual output of fruit), X4 (annual output of fresh vegetable) and X5 (annual output of sweet potato) and one dependent variable Y (morbidity of esophageal cancer) were studied by correlative analysis and multiple stepwise regression. Three correlative factors (X1, X2, and X5) with significant effect on the esophageal cancer were selected from the five suspected factors. The result indicated that taking sanitized water, reducing the number of people on pickled Chinese cabbage, changing the structure of food and keeping the nutrient balance, might decrease the incidence of esophageal cancer.