Background: Investigations on environmental tobacco smoke (ETS) exposure that include source intensity, childhood exposure, and association with histologic subtypes among never smoking lung cancer cases are limited. We report the patterns of ETS exposure history in a clinical cohort of women with newly diagnosed lung cancer.
Methods: From 1997 to 2001, 810 women with lung cancer were interviewed to obtain data including the source, intensity, and duration of ETS exposure. In this descriptive study, relationships between smoking history, ETS exposure, and lung cancer histologic subtypes were analyzed.
Results: Among the 810 patients, 773 (95.4%) reported personal smoking or ETS exposure including 170 of 207 (82%) never smokers. Among the never smokers with a history of ETS exposure, the mean years of exposure were 27 from a smoking spouse, 19 from parents, and 15 from co-workers. For each major subtype of lung cancer (adenocarcinoma, squamous cell, unclassified non-small cell lung cancer, small cell, or carcinoids) among never smokers, 75-100% of patients had ETS exposure. Trends for adenocarcinoma, squamous, and small cell carcinoma are statistically significant using the Cochran-Armitage Test for Trend (P<0.001) among never smokers without ETS exposure, never smokers with ETS exposure, former smokers, and current smokers.
Conclusions: Over 95% of women with lung cancer in our study were exposed to tobacco smoke through a personal smoking history or ETS. The cumulative amount of tobacco smoke exposure may be significantly underestimated if only personal smoking history is considered. Our results add to the public health implications of exposure to tobacco smoke and highlight the importance of eliminating tobacco smoking in public and private settings.