35PD - Magnitude of exposure to biomass fuel smoke and risk of lung cancer in women: Cases and controls study

Prevention, Early detection, Epidemiology, Tobacco control

35PD - Magnitude of exposure to biomass fuel smoke and risk of lung cancer in women: Cases and controls study

Authors

Renata Baez-Saldana (MX)
Uriel Rumbo-Nava (MX)
Alejandro Canseco-Raymundo (MX)
Patricia Castillo-Gonzalez (MX)
Santiago Leon-Duenas (MX)
Rosa Rivera-Rosales (MX)
Cesar Luna-Rivero (MX)

Presenter

Renata Baez-Saldana (MX)

Abstract

Abstract

Background

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. Data on lung cancer risk associated with the exposition magnitude of biomass fuel smoke in women are limited. The objective was to estimate the risk of lung cancer in women according to the magnitude of exposure to biomass cooking fuel smoke.

Methods

We designed a hospital-based case-control study. We included 136 cases of primary lung cancer anatomopathologically confirmed and 137 hospital controls of which 50 (27%) had interstitial lung diseases, 46 (25%) pulmonary tuberculosis, 43 (24%) pneumonia, 33 (18%) pulmonary embolism and 11(6%) had ear, nose and throat ailments. Exposure to wood smoke was assessed as a continuous variable based on the calculation of hour-years (years of exposure multiplied by average hours of exposure per day), as a categorical variable broken down in three categories (<100, 101–299, and >300 hour/years), and as any or none. 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 level. We repeated the same analysis but only including non-smoking women.

Results

Cases were older than the controls, 65 vs. 62 years old (p < 0.05) with higher rate of exposure to wood smoke (REWS), 144 vs 88 hour-years (p < 0.05), and the risk of lung cancer increased linearity with hour-years, OR 1.02 (95% CI 1.00–1.00) p = 0.019. Crude and adjusted odds ratios for an exposure >100 hour-years were OR 1.66 (95% CI 0.76–3.64) and OR 2.19 (95% CI 0.89–5.40) respectively, and for >300 hour-years OR 1.78 (IC95% 0.77–4.13) and OR 3.01 (95% CI 1.12–8.36). The association persisted after adjusting for sex, smoking, socioeconomic status and housing with asbestos sheet roof. In non-smoking women at an REWS >300 hour-years the risk increased to an OR 5.71 (95% CI 1.33–24.60).

Conclusions

These results provide novel evidence that the magnitude of exposure to biomass smoke in hour-years may play a crucial role in the chain of causation of lung cancer. The size of the pooled effect shows that the risk of lung cancer is higher in non-smoking women.