The incidence rates of gastric cancer in Shanghai urban districts have been markedly declining over the past three decades. From 1972 to 2001 the age-adjusted incidence rates of gastric cancer decreased from 62.0 to 32.5 per 100 000 in men and from 23.9 to 16.9 per 100 000 in women. This study aimed to investigate the relationship between environmental factors, in particular dietary factors, and the development of gastric cancer in those who lived in Shanghai urban districts for more than 15 years, and to explore the causes that led to the reduction of the incidence rates of gastric cancer in Shanghai.METHODS
One hundred and eighty-nine patients with gastric cancer and 567 age and sex-matched controls were surveyed with a questionnaire. SPSS software package was used to perform the univariate and multivariate unconditional logistic regression analysis modeling.RESULTS
Vitamin supplements, use of home refrigerators, high consumption of fresh fruits and vegetables, bean and dairy products, and good meal habits were protective factors against gastric cancer. However, family history of cancer, chronic gastric diseases, increased intake of salted, pickled, fried and smoked foods, poor meal habits, smoking and alcohol drinking were risk factors for gastric cancer.CONCLUSIONS
The reduction of the incidence of gastric cancer in Shanghai urban district in the past three decades is closely related to environmental factors, in particular dietary factors and wide use of home refrigerators.