Case Report: Hepatic sarcoidosis-like reaction from neoadjuvant pembrolizumab in early-stage triple-negative breast cancer.

Drug-induced sarcoidosis-like reaction (DISR) is a rare adverse event associated with immunotherapy. Currently, there is no standardized treatment protocol for DISR linked to immune checkpoint inhibitors (ICIs). This study presents a case of an early-stage triple-negative breast cancer (TNBC) patient who developed hepatic sarcoidosis-like reactions during neoadjuvant pembrolizumab therapy. We provide an overview of ICI-induced sarcoidosis-like reactions in cancer patients, including incidence, mechanisms, clinical manifestations, treatment, and prognosis. Additionally, we discuss the significance of one-year adjuvant immunotherapy for early-stage TNBC patients who achieved pathological complete response after neoadjuvant therapy, offering insights for individualized therapeutic strategies in this population.