Levonorgestrel intrauterine system for endometrial protection in women with breast cancer on adjuvant tamoxifen.

Adjuvant tamoxifen reduces the risk of breast cancer recurrence in women with estrogen receptor-positive breast cancer. Tamoxifen also increases the risk of postmenopausal bleeding, endometrial hyperplasia, polyps, and endometrial cancer. The levonorgestrel-releasing intrauterine system (LNG-IUS) causes profound endometrial suppression. This systematic review considered the evidence that the LNG-IUS prevents the development of endometrial pathology in women taking tamoxifen as adjuvant endocrine therapy for breast cancer.