Treatment Strategies for Oligometastatic Breast Cancer

Area of Science:

• Oncology
• Radiation Oncology
• Cancer Metastasis

Background:

• Oligometastatic breast cancer (1-5 metastases) is an intermediate stage with a unique molecular profile and better prognosis than widely metastatic disease.
• This condition's limited metastatic potential suggests benefit from aggressive, localized treatment of known metastases.

Purpose of the Study:

• To review the emerging evidence for aggressive ablative therapies in oligometastatic breast cancer.
• To discuss the role of hypofractionated image-guided radiotherapy (HIGRT) and its potential synergy with immunotherapy.

Main Methods:

• Review of the phase II SABR-COMET trial data comparing HIGRT to standard of care for oligometastatic disease.
• Discussion of ongoing clinical trials investigating ablative therapies, including HIGRT, with or without immunotherapy.

Main Results:

• The SABR-COMET trial demonstrated a survival advantage for patients treated with HIGRT.
• HIGRT may enhance immunotherapy efficacy by modulating the immune response and increasing tumor-infiltrating lymphocytes.

Conclusions:

• Select patients with oligometastatic breast cancer may be candidates for curative-intent ablative therapy, preferably within clinical trials.
• Criteria for ablative therapy include a longer disease-free interval, fewer metastases, and fewer involved organs.