Damage to DNA in cervical epithelium related to smoking tobacco.
OBJECTIVE
To determine whether tobacco smoking causes increased DNA modification (adducts) in human cervical epithelium.


METHODS
Comparison of DNA adducts measured by the technique of postlabelling with phosphorus-32 in normal ectocervical epithelium of smokers and non-smokers. A questionnaire on smoking habit and a urinary cotinine assay were used to identify smokers and non-smokers.


METHODS
Cytology unit in large teaching hospital.


METHODS
39 women (11 current smokers, seven former smokers, and 21 who had never smoked) undergoing gynaecological treatment (colposcopy or hysterectomy). Nineteen members of staff who did not smoke as controls.


METHODS
Biopsy of normal ectocervical epithelium. Urine sample.


METHODS
Measurement of DNA adducts in cervical epithelial tissue of smokers and non-smokers. Smoking habit derived from results of questionnaire and urinary cotinine:creatinine ratio. Proportion of adducts in women with abnormal and normal results of cervical smear test.


RESULTS
DNA samples from smokers (identified from questionnaire) had significantly higher median proportions of DNA adducts that non-smokers (4.62 (95% confidence interval 4.04 to 7.74) v 3.47 (2.84 to 4.78) adducts/10(8) nucleotides; p = 0.048). Exclusion of women whose urinary cotinine:creatinine ratio did not confirm their self reported smoking habit (smoker or non-smoker) increased this difference (4.7 (3.85 to 8.08) v 3.52 (2.32 to 4.95) adducts/10(8) nucleotides; p = 0.03). Women who had abnormal results of cervical smear tests had significantly higher proportions of adducts than those with normal results (4.7 (3.90 to 8.13) v 3.47 (3.06 to 5.36) adducts/10(8) nucleotides; p = 0.03).


CONCLUSIONS
Tobacco smoking by women leads to increased modification of DNA in cervical epithelium, suggesting biochemical evidence consistent with smoking as a cause of cervical cancer.
Simons
A M
AM
Cytology and Cytogenetics Unit, St Mary's Hospital Medical School, Faculty of Medicine, Imperial College, London.
Phillips
D H
DH
Coleman
D V
DV
D000328:Adult; D000368:Aged; D001345:Autoradiography; D002584:Cervix Uteri / Q000473:pathology*; D003127:Colposcopy; D004247:DNA / Q000032:analysis*; D004848:Epithelium; D005260:Female; D006801:Humans; D008875:Middle Aged; D012907:Smoking / Q000009:adverse effects / Q000235:genetics* / Q000473:pathology; D014626:Vaginal Smears
D004247:DNA