Is obesity a preventive factor for lung cancer?

Lung cancer is a disease with multifactorial etiology, smoking playing the most important role among its risk factors. Some studies, however, indicate an inverse association between increased body-mass index (BMI) and the risk of lung cancer. In this paper, the association between BMI and lung cancer risk is analysed in two independent studies. In the first study, 751 lung cancer patients were compared to 30 058 controls. In the second study, 91 lung cancer patients were matched to 91 healthy controls. An inversed association was found between increased BMI and lung cancer risk. The inverse association remained significant after adjustment for age, sex, and smoking.