Tamoxifen and ovarian cysts: a prospective study.

ABSTRACT

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 post-menopausal. 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 pre-menopausal 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.