Effects of Tamoxifen on the Cervix and Uterus in Women with Breast Cancer: Experience with Iranian Patients and a Literature Review

Objective: Invasive breast cancer is the most common malignancy in women. Due to the declining mortality rate that is partly attributable to the use of screening mammography and effective adjuvant therapy, more women survive their breast cancers. The aim of this study was to evaluate the effects of tamoxifen on the genital tract with particular attention to the uterus and cervix. Methods: We investigated the relationship between tamoxifen and cervical or uterine cancer in Iran, reviewing all the studies performed by the Vali-Asr Gynecology Oncology Clinic in Tehran. In addition, the available data on Medline from 1980 until 2009 were reviewed. Results: A total of 182 articles showed associations with gynecologic malignancies. Although as many as 121 refered to links between the drug and endometrial abnormalities (polyps or cancers), 55 articles studied the relationship with changes of pap smears, four of which indicated isolated cervical metastasis followed tamoxifen use in patients with breast cancer. Conclusion: In spite of the significant relationship between tamoxifen and endometrial cancers, cervix is rarely involved in breast cancer patients. However, vaginal bleeding or abnormal vaginal discharge has been reported in all cases before the diagnosis was made. To rule out genital tract malignancy, it is necessary, therefore, to have an annual pelvic exam, pap smear and early endometrial with endocervical curettage for tamoxifen users following a breast cancer in those with abnormal uterine bleeding or persistent vaginal discharge.