Role of active and passive smoking on lung cancer etiology in Mexico City.

OBJECTIVE [corrected] To estimate the association between passive and active smoking exposures and lung cancer in Mexico City and the corresponding attributable risks. MATERIAL AND METHODS Data was analyzed from a multicenter population-based case-control study conducted in Mexico City. RESULTS ORs for lung cancer in ever smokers were 6.2 (95% CI 3.9-10.2) for males and 2.8 (95% CI 1.7-4.4) for females. Passive smoking at home showed an overall OR of 1.8 (95% CI 1.3-2.6), similar in both genders. Attributable risk for active smoking for both genders combined, and for males and females separately, was estimated at 55, 76 and 27%, respectively. Attributable risk for passive smoking at home was 17% for females, 3.9% for males and 12% for the entire population. CONCLUSIONS In Mexico City smoking is attributable to a smaller proportion of lung cancer cases than in developed countries. This is explained by a lower intensity of smoking in the Mexican population.