Your new experience awaits. Try the new design now and help us make it even better

ORIGINAL RESEARCH article

Front. Oncol.

Sec. Breast Cancer

Adherence to Adjuvant Endocrine Therapy in Breast Cancer: A Single Regional Australian Centre Experience

Provisionally accepted
  • 1Department of Medical Oncology, Goulburn Valley Health, Shepparton, Australia
  • 2Department of Rural Health, Shepparton clinical School, The University of Melbourne Melbourne Medical School, Melbourne, Australia

The final, formatted version of the article will be published soon.

Introduction Adjuvant endocrine therapy reduces cancer recurrence and improves overall survival in hormone receptor–positive breast cancer. Maintaining long-term adherence to endocrine therapy can be challenging, and non-adherence has been associated with higher recurrence rates and reduced survival. Despite its importance, data describing adherence patterns in regional Australian populations are limited. This study aimed to assess adherence to adjuvant endocrine therapy in a regional Australian cancer center and to examine factors associated with non-adherence. Methods A cross-sectional survey was conducted at a regional Australian cancer center between March 2023 and July 2024. Eligible participants were women receiving adjuvant oral endocrine therapy for breast cancer. Adherence was assessed using the six-item Simplified Medication Adherence Questionnaire (SMAQ). Participants also reported treatment-related side effects. Results One hundred women were included, with a median age of 62.5 years. The adherence rate as determined by the SMAQ was 65%. Participants reported an average of 2.5 treatment-related side effects, with hot flashes being the most commonly reported (59%). Both the presence and number of reported side effects were associated with lower adherence. In multivariable analyses, a higher side-effect burden remained associated with adherence after adjustment for other covariates. Discussion This study demonstrates suboptimal adherence to adjuvant endocrine therapy in a regional Australian cohort and highlights treatment-related side effects and forgetfulness as key barriers to adherence. These findings underscore the importance of proactive side-effect management and practical adherence support strategies within regional cancer care settings.

Keywords: breast cancer, Endocrine therapy, Medication Adherence, Rural oncology, side effect

Received: 14 Sep 2025; Accepted: 03 Feb 2026.

Copyright: © 2026 BU, SAHU and Torres. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Javier Torres

Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.