A Study on Adding Precisely Targeted Radiation Therapy (Stereotactic Body Radiation Therapy) to the Usual Treatment Approach (Drug Therapy) in People With Breast Cancer

Study Overview
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Brief Summary
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The purpose of this study is to see if using Stereotactic Body Radiation Therapy/SBRT to treat a single metastatic site where cancer has worsened may be an effective treatment for people with oligometastatic breast cancer. Participants will stay on their usual drug therapy while they receive SBRT. This combination of SBRT to a single metastatic site and usual drug therapy may prevent participants' cancer from worsening in other metastatic sites or spreading.

Official Title
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Stereotactic Body Radiation Therapy (SBRT) to Extend the Benefit of Systemic Therapy in Patients With Solitary Disease Progression

Conditions
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Oligometastatic Breast Carcinoma, Breast Cancer, Metastatic Breast Cancer, Metastatic Breast Carcinoma, ER+ Breast Cancer, HER2+ Breast Cancer

Intervention / Treatment
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* Radiation: Stereotactic body radiotherapy


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age 18 or older Willing and able to provide informed consent Metastatic breast cancer, biopsy proven ER+/HER2-, defined as >5% ER+ staining HER2+ (regardless of ER status), including HER2-low and high expressors History of at least 6 months, sustained response to systemic therapy (clinically or radiographically defined as complete or stable response without progression) Isolated site of disease progression on FDG PET scan Consented to 12-245 ECOG performance status 0-1 Exclusion Criteria: Pregnancy Serious medical comorbidity precluding radiation, including connective tissue disorders Intracranial disease (including previous intracranial involvement) Previous radiotherapy to the intended treatment site that precludes developing a treatment plan that respects normal tissue tolerances.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Participants with oligometastatic breast cancer<br>Participants with oligometastatic breast cancer with isolated progression after sustained (>=6 month) response to systemic therapy. Participants will receive image guided, SBRT to the progressive lesion identified on imaging. Participants will be maintained on their existing line of systemic therapy. Systemic therapy will be held during days of radiation and resume following completion of radiation. | Radiation: Stereotactic body radiotherapy<br>* SBRT will be initiated as soon as possible, at not beyond 8 weeks of baseline measurements. Recommended dosing is per department standards for oligometastatic disease (ie, 10 Gy x 3 or 7-8 Gy x 5 fractions daily, excluding weekends and departmental holidays)<br>* Other names: SBRT;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Progression free survival | The primary objective is to assess progression free survival, defined as systemic progression or death, within 3 months from start of Stereotactic Body Radiation Therapy/SBRT delivery. | 3 months from start of SBRT delivery | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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oligometastatic breast cancer, breast cancer, ER+ Breast Cancer, HER2+ Breast Cancer, Metastatic Breast Cancer, Stereotactic Body Radiation Therapy, 22-259, Memorial Sloan Kettering Cancer Center