Primary Breast Oligoprogressive Sites Treated With Radiotherapy to Obviate the Need to Change Systemic Therapy (BOSS)

Study Overview
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Brief Summary
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This study assesses if metastasis-directed radiation therapy (Stereotactic body radiation therapy - SBRT) can delay a change in systemic therapy, and if circulating tumor cells in the bloodstream can help guide treatment options in metastatic breast cancer patients with progressive disease.

Detailed Description
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PRIMARY OBJECTIVE: I. To assess whether radiotherapy can provide clinically significant freedom from a change in systemic therapy (defined as for at least 6 months) for well-selected patients with oligoprogressive metastatic breast cancer. OUTLINE: This is an observational study. Patients undergo blood sample collection and complete questionnaires on study.

Official Title
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Primary Breast Oligoprogressive Sites Treated With Radiotherapy to Obviate the Need to Change Systemic Therapy (BOSS)

Conditions
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Breast Carcinoma

Intervention / Treatment
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* Other: Non-Interventional Study


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: * Age ≥ 18 years. Histological confirmation of primary breast cancer. Patients with metastatic breast cancer and at least 12 months of clinical response to first-line systemic therapy, with the subsequent development of 1-3 extracranial sites of oligoprogressive disease. NOTE: patients with de novo metastatic disease and those developed metastatic disease after initially localized disease can both be included. Patients with metastatic breast cancer and at least 6 months of clinical response to second-line systemic therapy (or further, e.g., third- or fourth-line), with the subsequent development of 1-3 extracranial sites of oligoprogressive disease. ECOG Performance Status (PS) ≤ 2. Negative urine or serum pregnancy test done ≤ 7 days prior to registration, for women of childbearing potential only. Ability to complete questionnaire(s) by themselves or with assistance. Provide written informed consent. Willing to return to enrolling institution for follow-up (during the Active Monitoring Phase of the study). Willing to provide blood samples for correlative research purposes. Exclusion Criteria: * Male patients. Nursing or pregnant women. Men or women of childbearing potential who are unwilling to employ adequate contraception. Patients with triple negative disease (negative for ER, PR, and HER2). • Active second primary malignancy > 3 extracranial sites of oligoprogressive disease Active CNS disease. Patients with asymptomatic and stable, treated CNS lesions (radiation and/or surgery and/or other CNS-directed therapy who have not received corticosteroids for at least 4 weeks) are allowed. Active connective tissue disease that is felt by the treatment team to pose an excess risk of toxicity. Prior radiation that overlaps with the intended treatment volume such that, in the opinion of the patient's Radiation Oncologist, radiotherapy to progressing sites will not be safe. NOTE: patients with some dose overlap with prior radiotherapy that is deemed safe by the patient's Radiation Oncologist can be included in the trial.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Observational<br>Patients undergo blood sample collection and complete questionnaires on study. | Other: Non-Interventional Study<br>* Non-interventional study<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Freedom from a change in systemic therapy | Freedom from a change in systemic therapy defined as no change in systemic therapy at 6 months after radiotherapy and patient survival at 6 months after radiotherapy. Treatment failure would indicate that there is no longer stability of systemic therapy (and thereby requires a change in systemic therapy to a different agent). | At 6 months |