The heterogeneity in risk factors of lung cancer and the difference of histologic distribution between genders in taiwan

Objective: The difference in histologic patterns of lung cancer between men and women in Taiwan may be associated with the heterogeneity in causal fac tors of lung cancer between the sexes. Methods: Cases consisted of 236 male and 291 female incident cases with new ly diagnosed and histologically confirmed primary carcinoma of the lung, an d were compared to one or two individually matched controls. Results: Cigarette smoking, occupations, and previous tuberculosis history were found to independently correlate with an elevated risk of squamous/sma ll cell carcinoma and adenocarcinoma for male patients. However, there was little difference in the effect of these risk factors except smoking. The u se of fume extractors in the kitchen, and the habit of waiting to fry after the fumes were emitted, separately explained the majority of the attributa ble fraction of female squamous/small cell carcinoma (28.2%) and adenocarci noma (47.7%). With the exception of a kitchen with fume extractors and a cl inical history of tuberculosis, the environmental causal factors of lung ca ncer were heterogeneous between these two histologic cell groups. Conclusions: Our results suggested that the causal factors of lung cancer m ight be specific for the type of tumor concerned. The gender-specific risk factors of lung cancer could partly explain the difference in cell-type dis tribution between men and women.