Risk factors for gastric cancer in South India.

INTRODUCTION Stomach cancer is the third most common cancer in South India. A higher incidence has been reported from certain states in northern India, where potential risk factors have been identified. Similar data is available only to a limited extent from southern India. The aim of this case-control study was to evaluate the effects of lifestyle habits and dietary factors on the risk of gastric cancer in South Indians. METHODS A hospital-based case-control study of matched pairs was conducted in Chennai, India, from 2002 to 2006 in a large tertiary care referral centre in South India. We studied 89 gastric cancer patients and 89 age- and gender-matched healthy controls of the same socioeconomic status. All subjects were interviewed face-to-face by a trained interviewer using a structured questionnaire to collect data about lifestyle habits, such as cigarette smoking, alcohol consumption, tobacco chewing and dietary factors, with special attention to known factors like salted fish, smoked and pickled foods as well as intake of vegetables and fruits. RESULTS The response rate was 100 percent. There were 64 male and 25 female patients. The male to female ratio was 2.6:1. The demographic characteristics were similar in the case and control populations. Less than ten percent of patients were below the age of 30 years. Approximately 50 percent were between 30 and 60 years of age, and the rest were over 60 years of age. Multivariate logistic regression models indicated that alcohol consumption (odds ratio [OR] 2.3, 95 percent confidence interval [CI] 1.1-4.9, p-value is 0.04) and consumption of pickled food (OR 1.8, 95 percent CI 1.2-3.9, p-value is 0.05) are independent risk factors for the development of gastric cancer. A protective effect of the consumption of pulses (OR 0.4, 95 percent CI 0.2-0.9, p-value is 0.05), showing a 55 percent reduction in risk, was also identified; this could be of use for possible control and prevention of this cancer. Tobacco chewing and cigarette smoking did not emerge as high risk factors for stomach cancer. CONCLUSION The study showed alcohol and pickled food consumption as independent risk factors for the development of gastric cancer, while consumption of pulses were protective. Cigarette smoking did not predict an increased risk of contracting the disease.