LIFE-STYLE AND RISK OF STOMACH-CANCER - A HOSPITAL-BASED CASE-CONTROLSTUDY

Background. Stomach cancer (SC) is the most frequent cancer among male s and third most common cancer among females in Madras, India. The inc idence rate of SC is higher in Southern India compared to Northern Ind ia. Methods. A hospital-based case-control study on 388 incident cases of SC was carried out in Madras as part of a multicentre study in Ind ia to identify the risk factors for SC. Cases were matched to cancer c ontrols based on age (+/- 5 years), sex, religion and mother tongue. C ategorical variables for income group, level of education and area of residence were included in all models to control for confounding. Resu lts. Smokers had a twofold risk of SC (95% confidence interval [CI] = 1.25-3.78) compared to non smokers and the risk seen among current smo kers (odds ratio [OR] = 2.5: 95% CI:1.36-4.44) was significantly diffe rent from that seen among exsmokers (OR = 1.5; 95% CI:0.67-3.54). The risk among those who smoke bidi (OR = 3.2; 95% CI:1.80-5.67) was highe r than that seen among cigarette (OR = 2.0; 95% CI:1.07-3.58) and chut ta (OR = 2.4; 95% CI:1.18-4.93) smokers. Significant dose response rel ationships were observed with age began smoking bidi (P < 0.001) and w ith lifetime exposure to bidi (P < 0.001), cigarette (P < 0.01) and ch utta (P < 0.05) smoking. The habits of drinking alcohol and chewing di d not emerge as risk factors. An interaction effect was not seen betwe en the lifestyle habits. Attributable risk (AR) for smoking among exsm okers was 33% and current smokers 60%. Population AR for smoking was 3 1%. Conclusion. Smoking tobacco is an independent risk factor for SC.