The effect of cigarette smoking on cell proliferation in normal uterine cervix epithelium.

Background: The aim of this study was to evaluate the effect of smoking on cell proliferation in normal cervical epithelium.

Methods: A total of 45 women undergoing hysterectomies due to uterine leiomyomata were investigated. Thirty were nonsmokers and 15 were current smokers. A segment of tissue was taken from cervix after removal of the uterus, and the identification of cell proliferation was performed by immunohistochemical analysis employing Ki-67 staining. The number of positive cells colored by Ki-67 staining was finally expressed as number of cells per square millimeter (mm²) of epithelium.

Results: The comparison of the number of proliferating cells measured by ki-67 staining among smoking and nonsmoking women did not show significant difference. Among smoking women, there was no significant difference related to the number of cigarettes smoked per day or time of consumption and epithelial cell proliferation. However, the total amount of cigarettes smoked throughout presented significant association with Ki-67 staining (p < 0.001); the number of proliferating cells per mm² increased proportionally to the increase in consumption of cigarettes.

Conclusions: The results indicated that there was no significant difference between cell proliferation in smokers and nonsmokers; however, it was shown that in the smokers' group, amount of cigarettes smoked during throughout lifetime can increase cell proliferation in normal cervical epithelium.