Successful Retreatment of Metastatic Triple-negative Breast Cancer With Immune Checkpoint Inhibitors and Chemotherapy

The efficacy of retreatment with immune checkpoint inhibitors (ICIs) in programmed death-ligand 1 (PD-L1) positive metastatic or recurrent triple-negative breast cancer (mTNBC) remains unknown. We report a case of a patient with recurrent triple-negative breast cancer who was successfully treated with two different ICIs in combination with chemotherapy.

A 60-year-old female patient was treated with neoadjuvant chemotherapy consisting of epirubicin + cyclophosphamide (EC) followed by docetaxel (DTX). The tumor shrank with EC, but progressed with DTX. One year after the surgery, the patient presented with multiple lung metastases. The patient received combination therapy with atezolizumab and nab-paclitaxel and achieved a partial response (PR). However, the disease progressed after 6 months. She received eribulin as second-line chemotherapy for 4.5 months, and her treatment was changed to pembrolizumab, carboplatin, and gemcitabine as third-line chemotherapy. The tumor immediately reduced and disappeared after three cycles of this treatment and achieved PR.

This case illustrated that retreatment with ICIs was effective.