ADHERENCE TO ENDOCRINE THERAPY IN BREAST CANCER: A DETERMINANT OF OUTCOMES
Author(s)
Hannah Evanik, PharmD (candidate)1, Aaron Mendelsohn, PhD, MPH2, Pamala A. Pawloski, PharmD3, Cate Lockhart, MS, PharmD, PhD4;
1Temple Univerisity School of Pharmacy, Philadelphia, PA, USA, 2Komodo Health, Rockville, MD, USA, 3Academy of Managed Care Pharmacy (AMCP), Alexandria, VA, USA, 4BBCIC, Asheville, NC, USA
1Temple Univerisity School of Pharmacy, Philadelphia, PA, USA, 2Komodo Health, Rockville, MD, USA, 3Academy of Managed Care Pharmacy (AMCP), Alexandria, VA, USA, 4BBCIC, Asheville, NC, USA
OBJECTIVES: Adherence to adjuvant endocrine therapies (AETs) is essential for management of breast cancer. We reviewed the findings from real-world, population-based studies to evaluate the impact of AET adherence on clinical and other outcomes with particular emphasis on trends across diverse care settings and populations to identify high-risk groups where adherence interventions may be most impactful.
METHODS: We conducted a scoping review of studies that evaluated medication adherence or persistence using real-world secondary data such as administrative claims or electronic medical records. Full text articles were identified from PubMed, EMBASE, and Web of Science using the terms compliance, adherence, administrative claims, real-world, and observational. Among 1,505 articles initially retrieved, 98 met the inclusion criteria. We identified three studies in breast cancer that examined adherence to AETs and reported outcomes including survival and healthcare resource utilization (HCRU).
RESULTS: Lower adherence, defined as a medication possession ratio (MPR) <80%, was consistently associated with worse outcomes including increased mortality risk and greater levels of HCRU. For example, one study conducted in an underserved population found a 10% increase in mortality risk among patients who were nonadherent to tamoxifen. In a study of patients with metastatic breast cancer, low AET adherence was associated with a 26% higher rate of outpatient visits.
CONCLUSIONS: These findings consistently demonstrate that poor adherence to AET compromises treatment effectiveness and may contribute to worse survival outcomes, even in early-stage disease. Interventions to support adherence to these medications would be warranted.
METHODS: We conducted a scoping review of studies that evaluated medication adherence or persistence using real-world secondary data such as administrative claims or electronic medical records. Full text articles were identified from PubMed, EMBASE, and Web of Science using the terms compliance, adherence, administrative claims, real-world, and observational. Among 1,505 articles initially retrieved, 98 met the inclusion criteria. We identified three studies in breast cancer that examined adherence to AETs and reported outcomes including survival and healthcare resource utilization (HCRU).
RESULTS: Lower adherence, defined as a medication possession ratio (MPR) <80%, was consistently associated with worse outcomes including increased mortality risk and greater levels of HCRU. For example, one study conducted in an underserved population found a 10% increase in mortality risk among patients who were nonadherent to tamoxifen. In a study of patients with metastatic breast cancer, low AET adherence was associated with a 26% higher rate of outpatient visits.
CONCLUSIONS: These findings consistently demonstrate that poor adherence to AET compromises treatment effectiveness and may contribute to worse survival outcomes, even in early-stage disease. Interventions to support adherence to these medications would be warranted.
Conference/Value in Health Info
2026-05, ISPOR 2026, Philadelphia, PA, USA
Value in Health, Volume 29, Issue S6
Code
EPH69
Topic
Epidemiology & Public Health
Topic Subcategory
Public Health, Safety & Pharmacoepidemiology
Disease
No Additional Disease & Conditions/Specialized Treatment Areas, SDC: Oncology