Endocrine therapy

Much of the evidence presented in the following sections on therapy for women with hormone receptor–positive disease has been considered in an American Society of Clinical Oncology guideline that describes several options for the management of these patients.[37] Five years of adjuvant endocrine therapy has been shown to substantially reduce the risks of locoregional and distant recurrence, contralateral breast cancer, and death from breast cancer.

The optimal duration of endocrine therapy is unclear, with the preponderance of evidence supporting at least 5 years of endocrine therapy. A meta-analysis of 88 clinical trials involving 62,923 women with hormone receptor–positive breast cancer who were disease free after 5 years of endocrine therapy showed a steady risk of late recurrence 5 to 20 years after diagnosis.[38][Level of evidence C2] The risk of distant recurrence correlated with the original tumor (T) and node (N) status, with risks ranging from 10% to 41%.