Pneumonitis During Neoadjuvant Chemoimmunotherapy for Triple-Negative Breast Cancer: A Case Report

Triple-negative breast cancer (TNBC) is commonly treated with standard chemotherapy regimens, with immune checkpoint inhibitors (ICIs) recently incorporated into neoadjuvant therapy, resulting in improved pathological complete response (pCR) rates and survival outcomes. However, the use of ICI therapies has also raised concerns regarding potential adverse events, including pneumonitis. In this report, we present a case of hyperacute treatment-related pneumonitis occurring shortly after pembrolizumab administration, followed by two recurrent episodes after paclitaxel re-exposure. Early discontinuation of chemoimmunotherapy followed by corticosteroid treatment led to rapid clinical improvement, followed by surgical intervention. This case highlights the diagnostic and management challenges associated with treatment-related pneumonitis in patients receiving combination chemoimmunotherapy, emphasizing the importance of early recognition and prompt intervention.