Ethnicity and H. Pylori as Risk Factors for Gastric Cancer in Malaysia: A Prospective Case Control Study

OBJECTIVE: To determine the risk factors for gastric cancer (GCA), with particular emphasis on ethnicity in our multiracial population. METHODS: A prospective case control study with ratio of cancer:controls of 1:2. Diagnosis of H. pylori was made by serology using the ELISA technique. Dietary intake was assessed by dietary recall over the preceding 6 months. RESULTS: Eighty-seven cases of GCA were enrolled. The cancers were predominantly distal in location and of the intestinal type. Risk factors identified following multiple logistic regression analysis were: Chinese race (OR 10.23 [2.87-36.47]), H. pylori (OR 2.54 [1.16-5.58]), low level of education (OR 9.81 [2.03-47.46]), smoking (OR 2.52 [1.23-5.15]), and high intake of salted fish and vegetables (OR 5.18 [1.35-20.00]) were identified as significant independent risk factors for GCA, while high intake of fresh fruits and vegetables was protective for GCA (OR 0.15 [0.04-0.64]). Chili intake was not a significant protective factor following multivariate analysis. CONCLUSIONS: Chinese race was a strong independent predictor of GCA. H. pylori was an important predictor of GCA with a 2.5-fold greater risk in our patients. Despite a high prevalence of H. pylori, the prevalence of GCA among Indians was low and this paradox can be appropriately called the "Indian enigma."