ABSTRACT
OBJECTIVE: To determine, through the micronucleus (MN) test, the cytogenetic effects of cigarette smoking on exfoliated cells from the uterine cervix in women with normal smears and women with inflammatory atypia, squamous intraepithelial lesion (SIL) (cervical intraepithelial neoplasia [CIN] 1-3) and cervical cancer. STUDY DESIGN: The study group consisted of 200 women divided into three subgroups: group 1 (n = 116), women periodically undergoing cervical cytology and residents of Salvador-Bahia; group II (n = 57), women residing in São Paulo and previously selected because of a possible cytopathologic test positive for such conditions as human papillomavirus infections or malignant or premalignant cervical lesions (CIN 1-3); group III (n = 27), inmates of the Tatuapé Penal Institution, São Paulo. All the women underwent cytologic and colposcopic examination, and biopsies were performed on 68 of them. RESULTS: Considering the samples as a whole and using the chi(2) test for rare events, the number of MNs in smokers was significantly greater than in nonsmokers. It was also greater in women with larger exposure to smoking. The occurrence of MN was significantly lower in women with normal smears (smokers and nonsmokers) than in those showing any kind of pathologic alteration. In nonsmokers the occurrence of MN was similar between those with inflammatory atypia (IA) or low grade (L) SIL (CIN 1) and significantly higher in women with more severe lesions or high grade (H) SIL (CIN 2 and 3). Smokers with LSIL (CIN 1) showed a higher number of MNs than nonsmokers with a comparable diagnosis and smokers with IA. No differences were observed when compared with smokers with HSIL (CIN 2 and 3). MN occurrence was not associated with other risk factors for SIL or cancer development, such as age at first coitus, number of sexual partners, multiparity and use of hormonal contraceptives. CONCLUSION: These results suggest that the mutagenic effect of cigarette smoking occurs in cervical cells and that the progression of SIL is associated with increased frequency of chromosomal damage. Moreover, the data suggest that cigarette smoking introduces an additional risk to the progression of low grade LSIL (CIN 1). MN testing would be helpful in monitoring smokers with this kind of lesion.
PIP: Previous studies have shown that cigarette smoking increases the risk of developing squamous intraepithelial lesion (SIL) and cervical cancer. The present study used the micronucleus test to assess the cytogenic effects of smoking on exfoliated cells from 3 subgroups of Brazilian women: group 1 (n = 116), women periodically undergoing cervical cytology; group 2 (n = 57), women with a possibly positive cytologic test for human papillomavirus or malignant or premalignant cervical intraepithelial neoplasia (CIN 1-3); and group 3 (n = 27), inmates of the Tatuape Penal Institute. Overall, micronucleus frequency was significantly greater in smokers than in nonsmokers. The occurrence of micronuclei was significantly lower in women with normal smears (regardless of smoking status) than in women with any evidence of pathologic alterations. In nonsmokers, micronucleus frequency was similar in women with inflammatory atypia or low-grade CIN and significantly higher in women with more severe lesions and CIN 2-3. Smokers with CIN 1 had more micronuclei than nonsmokers with a comparable diagnosis and smokers with inflammatory atypia. No differences were observed in comparisons with smokers with CIN 2-3. Micronucleus occurrence was not associated with age at first coitus, number of sexual partners, multiparity, or use of hormonal contraception. These findings suggest that the mutagenic effect of smoking occurs in cervical cells and that SIL progression is associated with an increased frequency of chromosomal damage. The data further suggest that smoking adds to the risk of progression of low-grade SIL (CIN 1). Micronucleus testing, along with the cervical cytologic smear, is recommended to monitor smokers with this type of lesion.
