Background: Postmenopausal breast cancer patients treated with tamoxifen have been found to have a high incidence of ovarian tumors. Transvaginal ultrasonography is an accurate and reliable method for measuring ovarian size. The purpose of this study was to establish normal values for basal ovarian volume in postmenopausal tamoxifen-treated patients and compare them with those established for healthy, postmenopausal women in the same population with no exposure to hormone treatment.
Methods: In a prospective open pilot study, the ovaries of 65 postmenopausal breast cancer patients treated for at least 6 months with tamoxifen were measured by transvaginal ultrasonography. From the same population, 311 healthy postmenopausal women with no exposure to hormone therapy were examined and served as controls. After matching for menopausal age, ovarian volume was compared between groups.
Results: Mean ovarian volume of postmenopausal tamoxifen-treated patients was persistently low through the menopause, whereas the mean ovarian volume of the controls was large, gradually decreasing up to the 10th menopausal year (8.6 +/- 2.3 and 2.8 +/- 2.1 cm3, respectively). Mean ovarian volume of the tamoxifen-treated patients was significantly lower than that of the controls during the initial menopausal years.
Conclusions: An ovarian volume that is considered within normal range for a specific menopausal age in a healthy postmenopausal woman is abnormal for a postmenopausal tamoxifen-treated patient.