Extended Endocrine Therapy: Is 5 Years Enough?

PURPOSE OF REVIEW: Women with hormone receptor (HR)-positive breast cancer remain at risk for cancer recurrence for decades. In this review, we address recent data regarding the benefits and risks of extended endocrine therapy.

RECENT FINDINGS: Ten years of treatment with either tamoxifen or an aromatase inhibitor resulted in superior disease-free survival compared to 5 years of treatment. However, there are risks associated with extended therapy with either class of medication. Multiparameter genetic tests are in development to individualize the risk of late breast cancer recurrence and predict benefit from extended endocrine treatment. Extended endocrine therapy is a promising strategy to reduce breast cancer recurrence in women with HR-positive breast cancer. This approach should be considered based on individual risk of cancer recurrence compared to potential benefit, comorbidities, and tolerance of therapy.