Background. Both active cigarette smoking and human papillomavirus (HPV) infection are known risk factors for cervical intraepithelial neoplasm (CIN). The association between second-hand smoke (SHS) and CIN has not been conclusively determined. We conducted a community-based case-control study to estimate the relationship between SHS and CIN. Methods. Potential study subjects were selected through Pap smear screening in Kaohsiung County, Taiwan. A total of 171 subjects with either their first case of inflammation (benign epithelial lesion) or >= CIN1 by biopsy confirmation were assigned to a case group; 5 13 normal subjects with negative findings by Pap smears or biopsies were assigned to a control group. Results. Non-smoking women exposed to more than 20 pack-years of cigarette smoke had a significantly greater risk of developing > CIN2 than unexposed non-smokers (adjusted OR=7.2, 95% CI=2.5-20.6). Among the women without HPV infections, the greater the severity of disease found in the groups (normal, inflammation, CIN 1, to CIN2), the more likely it was for the women to be exposed to SHS, a significant increasing trend (p=0.037). Conclusions. In addition to HPV infection and active cigarette smoking, exposure to SHS is a major risk factor for CIN among Taiwanese women. (c) 2006 Elsevier Inc. All rights reserved.
