NCT06055881Active, not recruiting
Primary Breast Oligoprogressive Sites Treated With Radiotherapy to Obviate the Need to Change Systemic Therapy
Primary Breast Oligoprogressive Sites Treated With Radiotherapy to Obviate the Need to Change Systemic Therapy (BOSS)
Source: ClinicalTrials.gov · Last updated 3 Sept 2026
Brief summary (registry, in English)
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
- Status (registry)
- Active, not recruiting
- Study type
- Interventional
- Enrollment
- 45 (actual)
- First submitted
- 20 Sept 2023
- Start date
- 23 Oct 2023
- Primary completion date
- 26 Oct 2026
- Lead sponsor
- Mayo Clinic
- Diseases
- Metastatic breast cancer
- NCT number
- NCT06055881
What you commit to
- Study type: Interventional
- Participants enrolled: 45
- From 23 Oct 2023 to the primary completion date, 26 Oct 2026
- 2 sites in 1 country
- Visits and tests: ask the trial team, the registry does not list them
Built from the registry fields of ClinicalTrials.gov. It describes the study, not your situation.
Who cannot take part
Copied verbatim from ClinicalTrials.gov and grouped by topic. Only the trial team decides who can take part.
Prior treatment
- 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.
Other illness
- Patients with triple negative disease (negative for ER, PR, and HER2).
- Active second primary malignancy
- More than 3 extracranial sites of oligoprogressive disease
Other
- Male patients.
- Nursing or pregnant women.
- Men or women of childbearing potential who are unwilling to employ adequate contraception.
Who the study is looking for
- 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, and who plan for the continuation of the current systemic therapy.
- NOTE: patients with de novo metastatic disease and those developed metastatic disease after initially localized disease can both be included.
- OR
- 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.
- Eastern Cooperative Oncology Group (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.
- Receiving radiation therapy as specified in the protocol.
Age in the registry: 18 years to - · Sex: Female · Does not accept healthy volunteers
Sites (2)
Sites in registry order. Save your city in your profile to sort them by distance.
| Site | City | Country | Site status |
|---|---|---|---|
| Mayo Clinic in Rochester Coordinator of this site? Confirm its status | Rochester | United States | Unknown status |
| Mayo Clinic in Arizona Coordinator of this site? Confirm its status | Scottsdale | United States | Unknown status |
This page is information, not medical advice. Discuss any trial with your doctor.