DNA ADDUCT ASSAY IN CERVICAL EPITHELIUM

Numerous epidemiological studies have shown that there is an associati on between smoking and cervical cancer. However, the essential evidenc e to show whether this relationship is casual or causal is lacking. Th e demonstration of DNA modification by tobacco components in the cervi cal epithelium would provide biochemical evidence to support a causal role. In this study, DNA from 39 cervical biopsies was analysed for th e presence of DNA adducts using the P-32-postlabelling technique. A qu estionnaire on smoking habit and a urinary cotinine assay were used to identify smokers and nonsmokers. DNA samples from smokers [identified from questionnaire] were found to have significantly higher adduct le vels than nonsmokers (Mann-Whitney one-tailed U-test, 95% CI > 0.339, P = 0.024). Exclusion of the women whose urinary cotinine levels did n ot confirm their self-reported smoking status (smoker or nonsmoker) in creased this significance (95% CI > a 508, P = 0.01). Women who had ab normal cervical smears had significantly higher DNA adduct levels than those with normal smears (95% CI > 0.439, P = 0.015). Monitoring of w omen with high DNA adduct levels may be a way of identifying women at risk of cervical cancer. These findings demonstrate that tobacco smoki ng by women leads to elevated levels of DNA adducts in cervical epithe lium and provides the biochemical evidence to support the concept that smoking is a cause of cervical cancer. Published 1994 Wiley-Liss, Inc .