A Review of Adherence to Oral Endocrine Therapy for Breast Cancer

Abstract

Endocrine therapy is a critical part of adjuvant therapy in women with hormone receptor-positive breast cancer. Endocrine therapies include Tamoxifen and the aromatase inhibitors, such as Anastrozole, Letrozole, and Exemestane. Women are non-adherent to these therapies following treatment for breast cancer even though they have been shown to reduce the risk of recurrence and death. Understanding adherence is important to establishing the extent of the clinical problem and need for possible interventions. The purpose of this research was to review published research on oral endocrine therapy adherence in women who have been diagnosed with breast cancer. The PubMed search engine with MeSH terms were used to identify relevant literature. Information on adherence definitions, measures, timing of assessments, and specific medications prescribed was abstracted into a table and evaluated. Findings demonstrated varied definitions and measures were used. Adherence was poorly differentiated from failure to initiate medication or medication persistence. Adherence to oral endocrine therapy post treatment for breast cancer is a complex phenomenon. More research is needed to facilitate the development of patient tailored complex interventions by exploring patients' needs and underlying processes influencing medication non-adherence.