Tamoxifen-induced endometrial cancer

Tamoxifen-induced endometrial changes in postmenopausal women with breast carcinoma are well-known. Due to the popularity of postoperative chemotherapy for breast cancer, chemotherapy-induced early menopause in women with breast cancer on tamoxifen treatment needs more attention, because these women have higher risk for endometrial cancers than premenopausal women.

From May 1995 to May 1997, three premenopausal women aged 46, 43, and 39 with breast cancer were treated in our center. All patients received standard surgery for their breast cancers followed by six courses of adjuvant chemotherapy and 5-year tamoxifen treatment. All patients were regularly followed-up at the Breast Cancer Center and evaluated annually at the gynecological clinics including pelvic examination, Pap smear and transvaginal sonography.

All patients became menopausal after six courses of chemotherapy ranging from three months to 14 months. The endometrial cancers occurred at 36 months, 28 months, and 33 months, respectively, after initial treatment for the breast cancers. Their last gynecologic examinations performed at six months, eight months and five months before the diagnosis of endometrial cancer showed nothing remarkable. Only one patient complained of vaginal spotting before diagnosis and the other two patients only complained of increasing purulent vaginal discharge. All patients received standard treatment for endometrial cancer and none of them died of their disease but one patient died of recurrent breast cancer 52 months later.

Women with breast cancer on tamoxifen treatment need more attention and frequent evaluation of their reproductive organs, especially postmenopausal (either spontaneous or chemotherapy induced) women, although the American College of Obstetricians and Gynecologists (ACOG) comments that no more than annual pelvic exams with Pap smears are needed in asymptomatic women.