# Guidance for Canadian Breast Cancer Practice: National Consensus Recommendations for the Systemic Treatment of Patients with HR+/HER2− Early Breast Cancer 2025

## TL;DR

This paper provides updated national guidelines for treating a common type of early breast cancer in Canada, focusing on personalized, evidence-based care to improve patient outcomes.

## Contribution

The paper presents the first national consensus recommendations for HR+/HER2− early breast cancer treatment in Canada, emphasizing tailored and patient-centered care.

## Key findings

- Neoadjuvant chemotherapy is recommended for high-risk or locally advanced HR+/HER2− breast cancer.
- Genomic testing is advised to guide chemotherapy decisions, especially in postmenopausal patients.
- CDK4/6 inhibitors are recommended to intensify endocrine therapy in higher-risk patients.

## Abstract

Hormone receptor-positive, HER2-negative (HR+/HER2−) early breast cancer is the most common type of breast cancer and can vary widely in how it behaves and responds to treatment. While endocrine therapy is the foundation of care, additional treatments such as chemotherapy, targeted therapies, and bone-strengthening agents are beneficial for some patients but not others. To support consistent, evidence-informed decision-making across Canada, REAL Canadian Breast Cancer Alliance developed national consensus recommendations for the systemic treatment of HR+/HER2− early breast cancer. These recommendations address the use of treatments before and after surgery, incorporate tumour biology, stage, menopausal status, and patient preferences, and emphasize shared decision-making. The goal of this guidance is to help clinicians tailor treatment intensity to individual risk, avoid overtreatment where possible, and improve outcomes for patients across all provinces and territories.

Hormone receptor-positive, human epidermal growth factor receptor 2-negative (HR+/HER2−) early breast cancer (EBC) is the most common breast cancer subtype and encompasses a biologically heterogeneous group of tumours. Endocrine therapy (ET) remains the cornerstone of treatment, but decisions regarding chemotherapy, cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors, and bone-modifying agents must be tailored to tumour biology, clinical stage, and menopausal status. REAL Canadian Breast Cancer Alliance (REAL Alliance), a pan-Canadian group of breast cancer specialists, convened to develop national clinical consensus recommendations for the systemic management of HR+/HER2− EBC. Using a structured consensus process, 28 recommendations were endorsed, spanning neoadjuvant and adjuvant systemic therapy, surgical considerations, and use of bisphosphonates. Key recommendations include the selective use of neoadjuvant chemotherapy for high-risk or locally advanced disease; genomic testing to guide chemotherapy decisions, particularly in postmenopausal patients; ET as the foundation of adjuvant therapy with intensification using CDK4/6 inhibitors in higher-risk patients; and adjuvant bisphosphonates in postmenopausal women to reduce recurrence and improve survival. These consensus recommendations provide practical, evidence-based guidance to support individualized, patient-centred management of HR+/HER2− EBC in the Canadian context.