Tamoxifen and proliferation of vaginal and cervical epithelium in postmenopausal women with breast cancer

Objective: The estrogenic effect of tamoxifen on vaginal and cervical epithelium in postmenopausal women with breast cancer is evaluated. Study Design: The tamoxifen group consisted of 92 postmenopausal breast cancer patients, the control group I of 30 postmenopausal women with breast cancer receiving no endocrine therapy and the control group II of 40 postmenopausal women without primary breast cancer taking no hormones. We determined the maturation index and the incidence of endocervical cell hyperplasia and metaplasia in cervical and vaginal smears. Results: The maturation index increased under tamoxifen within the first 24 months from 0.4011 before taking tamoxifen (n = 56) to 0.6039 (n = 138, P<0.0001). The maturation index in the group treated with tamoxifen was statistically significantly higher (P<0.0001) than in the control groups (control group I: 0.3975, P<0.0001; control group II: 0.4102, P<0.0001). Under therapy with tamoxifen endocervical cell hyperplasia (P=0.00156) and metaplasia (P=0.00123) appeared significantly more often. Conclusion: An apparent increase not only of the incidence of endocervical cell hyperplasia and metaplasia but also of the maturation of the vaginal epithelium caused by the estrogenic effect of tamoxifen could be demonstrated.