Mutagenic mucus in the cervix of smokers.

A pilot study was conducted to determine whether any relationship exists between mutagenicity of a women's uterine cervical mucus and her current smoking status. Cervical fluids obtained from 78 premenopausal women seen between July 1983 and March 1984 at the University of California, San Francisco Dysplasia (and diethylstilbestrol) Clinic or in a private practice were tested for mutagenicity by means of the Ames-Salmonella microsomal test. Of 36 current smokers, 14 (39%) had positive tests as compared to 5 of 42 nonsmokers (12%). The odds ratio (OR) estimate was 4.7 with 95% confidence limits (CL) of 1.6-14.2. Secretions from 14 of 32 (44%) women who had smoked during the day of the sample collection--within the previous 7 hours--were positive on the laboratory test, whereas none of the 4 women was positive who had smoked 8 hours or more before the specimens were obtained. Fluids from women with dysplasia or carcinoma in situ were more likely to be mutagenic than were those from other women, although this finding may be due to chance (OR = 2.0 with 95% CL of .70-5.9). This relationship between smoking and mutagenic cervical fluids offers evidence that might help to explain the association between cervical cancer and cigarette smoking noted in previous epidemiologic studies.