Exposure to Wood Smoke and Risk of Lung Cancer: A Case Control Study

SESSION TITLE: Lung Cancer II SESSION TYPE: Original Investigation Poster PRESENTED ON: Wednesday, October 26, 2016 at 01:30 PM - 02:30 PM PURPOSE: Introduction Although smoking is the major risk factor for lung cancer worldwide, approximately 1.5% of annual lung cancer deaths are attributed to exposure to carcinogens from indoor solid fuel use. Biomass fuels is classified as a probable carcinogen. However, data on the magnitude of lung cancer risk associated with biomass cooking fuel smoke are limited. Purpose To estimate the risk of lung cancer in patients exposed to biomass cooking fuel smoke. METHODS: We designed a hospital-based case-control study. Cases had an anatomopathological confirmed primary lung cancer. Exposure to wood smoke was assessed as any or none, as a categorical variable, and as a continuous variable based on the calculation of hour-years (years of exposure multiplied by average hours of exposure per day). We used unconditional logistic regression to compute odds ratio (OR) and 95% Confidence Intervals (95% CI) for lung cancer risk associated with biomass cooking fuel smoke exposure, adjusting for potential confounders (tobacco use, age, gender, and socioeconomic status. RESULTS: We included 138 cases and 183 controls, of which 50 (27%) with interstitial lung diseases, 46 (25%) patients with pulmonary tuberculosis, 43 (24%) with pneumonia, 33 (18%) with pulmonary embolism and 11 (6%) with ear, nose and throat ailments. The rate of exposure to wood smoke was higher in cases vs controls, 144 and 88 hour-years (p < 0.05). Exposure to wood smoke as a dichotomous variable was not associated to the development of lung cancer, odds ratio 1.03 (95% CI 0.66-1.61). The OR for wood smoke exposure in hour-years were 1.02 (95% CI 1.00-1.00) p = 0.019. Risk of lung cancer increased linearly with hour-years of cooking with a wood stove, we observed an OR of 2.6 (2.6 (95% CI 1.05-6.44) for individuals exposed to > 100 hour-years compared with those exposed to < 100 hour-years. The association between exposure to wood smoke persisted after adjusting for sex, smoking, socioeconomic status and housing with asbestos sheet roof. CONCLUSIONS: These results suggest that exposure to biomass cooking fuel smoke may play a crucial role in the risk of lung cancer. CLINICAL IMPLICATIONS: Indoor air pollution from biomass cooking fuel smoke is the cause of significant global mortality and morbidity, and is a major health concern in developing world. DISCLOSURE: The following authors have nothing to disclose: Renata Baez-Saldana, Alejandro Canseco-Raymundo, Uriel Rumbo-Nava, Patricia Castillo-Gonzalez, Jazmín Chavez-Macias, Santiago Leon-Duenas, Rogelio Garcia-Torrentera No Product/Research Disclosure Information