Tumor Mutational Burden May Guide Treatment in Metastatic Breast Cancer

A recent study highlighted at the San Antonio Breast Cancer Symposium has shed light on the potential of tumor mutational burden (TMB) to guide treatment decisions in metastatic breast cancer. Specifically, the research focused on hormone receptor-positive, HER2-negative metastatic breast cancer patients, comparing the efficacy of pembrolizumab (Keytruda) versus chemotherapy.

Key Findings:

• Patients with a high TMB (above 10) experienced numerically more favorable survival outcomes when treated with pembrolizumab.
• No significant benefit was observed in patients with a TMB below 10.
• Pembrolizumab is noted as a less toxic alternative to chemotherapy, offering a potentially easier treatment option for patients to tolerate.

Mariya Rozenblit, MD, from Yale School of Medicine, emphasized the importance of considering pembrolizumab as a viable treatment option, especially for patients in the third or later lines of therapy. She also highlighted the necessity of consistent TMB testing to identify patients who may benefit from this treatment approach.

This study underscores the evolving landscape of breast cancer treatment, where personalized medicine based on genetic markers like TMB could play a crucial role in improving patient outcomes.