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.".