Lung cancer in women: the importance of smoking, family history of cancer, and medical history of respiratory disease.

The importance of smoking and other factors for lung cancer in women was investigated in a case-control study of women who had previously received a multiphasic health checkup at Northern California Kaiser Hospitals. Smoking and medical histories for 217 cases and matched controls were obtained from the multiphasic questionnaire. Odds ratios (ORs) and confidence intervals (CIs) associated with cigarette smoking were 35.1 (95% CI 4.8-256) for squamous and small cell and large cell carcinomas combined and 2.5 (95% CI 1.3-5.1) for adenocarcinoma. After adjusting for smoking, risk was increased in women with a family history of lung cancer (OR 1.9, 95% CI 0.7-5.6) and family history of any cancer (OR 1.8, 95% CI 1.0-3.2). A significant interaction existed between smoking and family history. Women with a history of bronchitis, pneumonia, or emphysema were at increased risk, whereas women with a history of asthma or hay fever experienced a significantly lower risk for lung cancer.