EFFECT OF SMOKING CESSATION ON CERVICAL LESION SIZE

Background Cigarette smoking has been postulated as a cofactor in the aetiology of cervical cancer, but a causal role is difficult to establ ish because of potential confounding by sexual behaviour. We have inve stigated the effect of cessation or reduction in cigarette smoking on the course of minor-grade cervical lesions. Methods In this interventi on study 82 women volunteers with minor-grade lesions on colposcopy (c ervical intraepithelial neoplasia grade 1 or less) attempted to give u p smoking for 6 months. Smoking histories were taken at 3-monthly clin ic visits and verified by measurement of salivary cotinine concentrati ons. At each clinic visit, a photograph of the cervix was taken; the i mage was digitised and computer-aided image analysis was used to asses s lesion size, by investigators unaware of smoking status. Findings Of the 82 women, 17 stopped smoking completely for at least 6 months and 11 others reduced their smoking consumption by more than 75%. Of thes e 28 women, 23 (82%) showed a reduction in lesion size of at least 20% or 4 mm(2) compared with 13 (28%) of the 47 non-quitters (odds ratio 12.0 [95% CI 3.9-32.7]). The remaining seven women had unconfirmed smo king histories. There was a significant correlation between the extent of smoking reduction and the change in lesion size (chi(2) for trend= 31.55, p<0.0001). Adjustment for social class, method of contraception , and stage of menstrual cycle did not affect the results. Interpretat ion Our findings support a link between smoking and cervical disease a nd suggest that smoking cessation could have a beneficial effect on ea rly cervical abnormalities.