A case-control study of risk factors for lung cancer in Mumbai, India

In the year 2010, it is estimated that nearly 1.35 million new cases and 1.18 million deaths with lung cancer occurred. In India, among males, lung cancer rates vary across the country which has encouraged us to conduct a case-control study to study the risk factors. The present unmatched hospital-based case-control study conducted at Tata Memorial Hospital included subjects registered between the years 1997-99. There were 408 lung 'cancer cases' and 1383 'normal controls'. Data on age, tobacco habits, occupational history, dietary factors, tea, coffee were collected by the social investigators. Univariate and regression analysis were applied for obtaining the odds ratio for risk factors. In the study, cigarette smoking (OR=5.2) and bidi smoking (OR=8.3), as well as alcohol consumption (OR=1.8), demonstrated dose-response relationships with lung cancer risk. Among the dietary items, only red-meat consumption showed 2.2-fold significant excess risk. Consumption of milk showed a 60% reduction in risk; while coffee showed a 2-fold excess risk for lung cancer. In addition, exposure to use of pesticides showed a 2.5-fold significant excess risk for lung cancer.