Objective: To investigate the relationship between body mass index (BMI) and lung cancer in non-smoking women.
Methods: A population-based case-control study on lung cancer in non-smoking women was conducted during February 1992 to December 1993 in Shanghai. Totally, 504 cases of lung cancer of non-smoking women and 601 population controls were studied.
Results: The risk of lung cancer increased with the decrease of BMI. The odds ratio of lung cancer in non-smoking women was 1.95, as compared to controls with the highest quartile of their BMI, with a dose-response pattern (P < 0.0002 with chi(2) test for trend), adjusted for age, schooling and income. Non-conditional logistic regression analysis was used to adjust for some main risk factors found in other studies carried out at home, such as passive smoking, tea drinking, eye irritation by cooking oil fume, kinds of cooking oils, pulmonary tuberculosis, family history of lung cancer, age of menarche, menstrual cycle and dietary nutrition (including intake of vitamins C and E, beta-carotene, total fat and calorie), was used to adjust. There still existed relationship between BMI and lung cancer in non-smoking women after adjustment for those factors. Stratification analysis showed that there was relationship mainly between BMI and lung adenocarcinoma.
Conclusion: BMI may be a risk factor for lung cancer in non-smoking women.