Tamoxifen and ovarian cysts: a prospective study

Purpose: To prospectively follow a group of women with breast cancer on tamoxifen for the development of ovarian cysts. Methods: 72 women were followed every 6 months with pelvic examination and vaginal ultrasound. Chi square and Student's t-test were used for statistical analysis. Results: The duration of treatment was 31.5 +/- 20 months. The mean age was 51.2 +/- 9.8 years. 55.6% were postmenopausal. Out of 72 women, 18 (25%) developed ovarian cysts. The mean age of women who developed ovarian cysts was significantly lower than in those who did not (47.0 +/- 7.0 and 52.5 +/- 10.2 years, respectively. P = 0.03), however, the mean duration of treatment was not significantly different (33.3 +/- 17.4 and 29.3 +/- 20 months. respectively, P = 0.45). Out of 32. 14 (43.8%) pre-menopausal and out of 40. 4 (10%) post-menopausal women developed ovarian cysts (P = 0.003). They developed the cysts after an average duration of 33.3 +/- 18 and 50.7 +/- 6.2 months. respectively (P = 0.7). The average diameter of the cysts was 2.8 +/- 1.2 cm. All cysts were simple except for one premenopausal women. All the cysts in post-menopausal women resolved spontaneously. One pre-menopausal patient had a multi-loculated cyst, was operated and had a serious cystadenoma. In nine patients. the cysts resolved spontaneously and in three after discontinuation of tamoxifen, and one patient was lost to follow-up. All cysts were asymptomatic. Conclusion: Ovarian cysts frequently develop in women with breast cancer on tamoxifen. The majority of the cysts resolve spontaneously. therefore an expectant management with follow-up ultrasonography is recommended, (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.