The association between cigarette smoking and low-grade cervical abnormalities in reproductive-age women

To evaluate the association between smoking and the occurrence of low-grade cervical cytological abnormalities.

We conducted a population-based cross-sectional study of smoking and other exposures in reproductive-age women with normal and abnormal cytology results (Class 1-4 Pap tests). Participants (n = 2,448) were enrollees of the Group Health Cooperative of Puget Sound, a health maintenance organization (HMO) in Washington state, USA. Non-pregnant women were selected monthly from the HMO's cytology database during 1995-6, with over-sampling of women with low-grade abnormalities. All participants completed a structured telephone-administered survey.

Of the 2,448 participants, 19% (n = 465) had Class 2 Pap results, and 5% (n = 117) had Class 3-4 results. Forty percent of the sample (n = 975) reported ever smoking. Women reporting current/recent smoking (n = 514, 21%) had an increased likelihood of cervical abnormalities (adjusted odds ratio (OR) 1.4, 95% confidence interval (CI 1.1-1.8). Women who had never smoked but who reported recent passive smoking exposure also had a greater likelihood of abnormal test results (OR 1.4, 95% CI 1.0-2.0). Prior smoking was not associated with cytology status.

Our results, examining low-grade cervical abnormalities, are compatible with those from studies of more severe cervical lesions, lending added support to the hypothesis that smoking predisposes to development of a spectrum of cervical abnormalities. Thus, even cytologic screening visits represent an opportunity to counsel women smokers about their health risks, particularly the more proximal risks of cervical abnormalities and cancer.