Recognition and management of treatment-related side effects for breast cancer patients receiving adjuvant endocrine therapy

In postmenopausal women with hormone receptor-positive early-stage breast cancer, the use of aromatase inhibitors (AIs) to suppress estrogen is associated with improved clinical outcomes compared with tamoxifen therapy. Women receiving such endocrine therapy may experience treatment-related side effects that negatively affect health-related quality of life (QoL) and adherence to therapy. In published clinical trials and in clinical practice, adverse events (AEs) constitute the main reason for non-adherence to endocrine treatment. Serious AEs are sometimes resolved by switching to a different agent, whereas other side effects can often be managed to allow patients to remain on therapy without sacrificing QoL. Across all adjuvant endocrine trials, regardless of the treatment received, vasomotor symptoms such as hot flashes are the most common side effects. Other frequently reported side effects, such as vaginal discharge, vaginal dryness, dyspareunia, and arthralgia, vary in prevalence between tamoxifen and AIs. Here we provide an overview of reported AEs of adjuvant endocrine therapy, focusing on those that are amenable to pharmacologic or nonpharmacologic management without treatment discontinuation. Also highlighted are specific management strategies that may improve patient QoL and thereby optimize adherence to therapy, which in turn might improve patient outcomes.