Continuing the Same Systemic Therapy After Local Ablative Treatment for Limited Progression in Metastatic Breast Cancer - COSMO Study

What this Trial Is About

Researchers are studying patients with metastatic breast cancer who experience oligoprogression during palliative treatment that can be treated locally. This phase 2 study focuses on evaluating local ablative therapies such as surgery, stereotactic ablative radiotherapy SABR, and radiofrequency ablation RFA to treat progressing lesions while continuing systemic therapy. The aim is to understand how these local treatments affect disease progression and patient outcomes. The local ablative therapy will target one or two progressing metastatic lesions, which may be located in one organ, the primary tumor, or locoregional lymph nodes. Treatment options include surgery, radiotherapy, or radiofrequency ablation, chosen based on the lesions location and standard care decisions by the treating medical team. Systemic therapy with endocrine, targeted, chemotherapy, or immune-checkpoint blockade will be ongoing for at least six months before and during this local treatment. Participants will be monitored for disease progression, with the primary outcome measuring the number of patients free from progression at 6 months. Evaluations include imaging scans, such as FDG-PET-CT, to confirm oligoprogression and assess treatment response. Secondary outcomes include progression by breast cancer subtype, overall survival up to 120 months, time to next treatment, and complications after local ablative therapy. The study involves informed consent, regular follow-ups, and safety monitoring throughout the trial period.

COntinue the SaMe Systemic Therapy After Local Ablative Therapy for Oligo Progression in Metastatic Breast Cancer - the COSMO Study