Severe Toxicities Associated with Immune Checkpoint Inhibitors in Early Triple-Negative Breast Cancer: Are the Results Worth the Price?

Immune checkpoint inhibitors (ICIs) have emerged as a promising therapeutic approach in the management of early triple-negative breast cancer (TNBC), significantly improving pathological complete response rates and survival outcomes.However, the use of ICIs is associated with a spectrum of immune-related adverse events (irAEs), ranging from mild symptoms to severe, lifethreatening toxicities.This case series reports the clinical course of three cases of patients with early-stage TNBC treated with neoadjuvant chemotherapy including ICIs who experienced severe toxicities, necessitating effective immunosuppressive therapy and discontinuation of systemic cancer treatment.Despite achieving a pathological complete or partial response following neoadjuvant systemic therapy (carboplatin/paclitaxel q1w with pembrolizumab q3w) and subsequent breast conserving surgery and adjuvant radiotherapy, the patients journey underscores the need for vigilant monitoring, multidisciplinary management, and judicious decision-making when incorporating ICIs into early TNBC treatment protocols.We observed in those three cases, with curative prognostic intention, irAEs ranging from CTCAE Grade III-IV including severe ARDS.Some of those irAEs were long lasting in nature.Our cases underscore the broad spectrum of immune-related side effects and emphasize the importance of early recognition, a multidisciplinary approach, and careful selection of patients who are most likely to benefit from this therapy.