NCT06937281

SABR PRIMER - Evaluating Stereotactic Ablative Radiotherapy for Primary and Regional Breast Tumors

A Phase II Trial Evaluating Stereotactic Ablative Radiotherapy for Primary and Regional Breast Tumors (SABR-PRIMeR)

• Status: Not Yet Recruiting
• Phase: N/A
• Study type: Interventional
• Enrollment: 40 (estimated)
• Sponsor: British Columbia Cancer Agency · Academic / Other
• Sex: All
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

The study is being done to determine if stereotactic ablative radiotherapy (SABR) can control tumour growth for patients with metastatic breast cancer. Secondary objectives will be overall survival, progression-free survival and time to switch of next line of systemic therapy. Radiation-related adverse events will be assess, with a specific focus on dermatitis, lymphedema and brachial plexopathy. The exploratory objective is to correlate toxicities and outcomes with peripheral blood biomarkers and circulating tumor DNA to potentially help predict responses in future patients receiving combined therapy.

Detailed description

Purpose: The purpose of this study is to determine if stereotactic ablative radiotherapy (SABR) can provide effective locoregional control for patients with metastatic breast cancer. As secondary objectives, the investigators will assess the overall survival, progression-free survival and time to switch of next line of systemic therapy. The investigators will also assess radiation-related adverse events using CTCAE v5.0, with a specific focus on dermatitis, lymphedema and brachial plexopathy. Finally, as an exploratory objective, the investigators aim to correlate toxicities and outcomes with peripheral blood biomarkers and circulating tumor DNA to potentially help predict responses in future patients receiving combined therapy. Primary Objective: • Assess median, 1-year and 2-year locoregional control Secondary Objectives: * Assess median, 1-year and 2-year overall survival * Assess median, 1-year and 2-year progression-free survival * Assess median time to systemic therapy switch * Assess radiation-related adverse events using CTCAE v5.0 Correlative Objectives: • Correlate outcomes with peripheral blood-derived parameters Research Design The trial is designed as a single-arm interventional study investigating stage IV breast cancer with persistent or progressive locoregional disease despite the use of standard systemic therapy A retrospective study will be conducted to create a matched cohort to compare locoregional control rates with patients who received conventional fractionated radiotherapy.

Conditions

• Breast Cancer
• Metastases

Interventions

Type	Name	Description
RADIATION	SABR	Prescription dose/fractionation: 26Gy/5 with 40Gy/5 +/- 35Gy/5 Boost Radiation Technique: VMAT Treatment Frequency: Every other day (EOD)

Timeline

• Start date: 2025-07-01
• Primary completion: 2029-06-30
• Completion: 2030-07-30
• First posted: 2025-04-22
• Last updated: 2025-04-24

Locations

1 site across 1 country: Canada