Setting the Stage: VMS in Patients with Breast Cancer on Endocrine Therapy

Vasomotor symptoms (VMS) represent one of the most clinically significant toxicities associated with endocrine therapy in patients with breast cancer. In this video, Carmine Valenza, MD, MPH, PhD(c), medical oncologist and research fellow at Istituto Europeo di Oncologia, Milan, and Dana-Farber Cancer Institute, Boston, Massachusetts, notes that VMS—including hot flashes and night sweats—are reported in more than 50% of patients on antiestrogen therapy and in up to 90% of younger patients receiving ovarian function suppression. Far from being a minor inconvenience, these symptoms carry measurable consequences for both patient well-being and oncologic outcomes.

The clinical burden of VMS extends well beyond subjective discomfort. According to Valenza, recent studies demonstrate that more than 20% of patients are nonadherent to endocrine therapy specifically because of VMS. Because lower adherence is associated with higher rates of disease recurrence and reduced survival, the treatment of VMS must be understood as an integral component of comprehensive breast cancer management rather than a secondary concern.

Historically, clinicians have had limited tools to address VMS in this population. Menopausal hormone therapy—although the most effective option for VMS in the general population—is generally contraindicated in patients with a history of breast cancer. Prior to the availability of neurokinin (NK) receptor antagonists, available pharmacologic alternatives included gabapentin (the only agent formerly preferred by National Comprehensive Cancer Network guidelines), selective serotonin reuptake inhibitors, and oxybutynin, each with modest efficacy. Nonpharmacologic strategies such as yoga, acupuncture, and weight control were also used but offered limited relief. Valenza emphasizes that the therapeutic landscape has since shifted substantially with the development of NK receptor–targeting agents.