Smoking and invasive cervical cancer risk. Results from a case-control study

The association between cigarette smoking and risk of invasive cervical cancer was investigated in a case-control study conducted in four hospitals in Leipzig, German Democratic Republic in 1983-1985. Analyses were based on 225 women aged 64 years or younger with newly diagnosed invasive cervical cancer and 435 age-matched controls with orthopedic or skin diseases. The crude relative risk of invasive cervical cancer was significantly elevated for women who had ever smoked (relative risk (RR) = 1.5, 95% confidence interval (CI) = 1.1-2.1). Adjustment for number of sexual partners reduced the risk to RR = 1.2 (95% CI = 0.8-1.6). Furthermore, the risk for smokers depended significantly on number of sexual partners (p less than 0.05) and was increased only among women with no partner or one partner (RR = 2.7, 95% CI = 1.2-6.1).