Side effects and impacts of extended adjuvant endocrine therapy: A qualitative study among women with HR+/HER2-breast cancer

e12509 Background: Extended (≥5-year) adjuvant endocrine therapy (ET) is generally the preferred treatment approach for patients with hormone receptor–positive (HR+) breast cancer at high risk of recurrence. However, due to side effect burden and other challenges, patient adherence to extended adjuvant ET is often suboptimal, presenting challenges for patients and healthcare providers alike. To further understand potential barriers to adherence, the objective of this study was to explore the side effects and impacts of extended adjuvant ET among women with HR+ breast cancer through in-depth qualitative interviews. Methods: Individual qualitative interviews were conducted with 20 US women with a self-reported clinical diagnosis of nonmetastatic HR+/HER2− breast cancer who had undergone ≥4 years of adjuvant ET and were currently taking ET or had concluded their regimen within the past 12 months. Using thematic analysis methods, interview transcripts and interviewers’ field notes were analyzed to identify important concepts and dominant trends. Results: Interview participants averaged 52.8 years in age and were diverse in race, education level, and employment status. The most commonly reported ET side effects among the 20 participants were hot flashes (n = 16), joint pain (n = 15), difficulty sleeping (n = 15), difficulty with weight management (n = 15), fatigue (n = 15), reduced interest in sex (n = 14), and feeling irritable (n = 14). Participants most frequently identified joint pain (n = 8), reduced interest in sex (n = 4), and discomfort with intercourse (n = 4) as the most bothersome ET side effects. Participants generally reported that the frequency and severity of side effects that they experienced remained constant throughout the extended adjuvant period; only 3 reported having switched ET regimens to manage side effects. Participants reported numerous impacts from ET side effects, including to cognitive and physical functioning (most common), social interactions, and work/productivity. Several participants spoke about the tradeoffs they make in enduring ET side effects and impacts to reduce risk of recurrence. For most participants, the primary benefit of extended adjuvant ET was the perceived reduction of risk of recurrence; some reported “peace of mind” from taking ET, knowing they were doing everything possible to reduce their risk of recurrence. Several participants expressed reluctance to stop taking ET despite the side effects because adherence to their medication made them feel less anxious or worried about recurrence. Conclusions: Patients receiving ET for HR+/HER2− breast cancer continue to experience significant side effects during extended adjuvant ET, and these side effects impact quality of life in many ways. Some patients are nonetheless motivated to continue with long-term ET to reduce risk of recurrence and/or because of the emotional benefit it affords.