A Case Series: High PD-L1 Expression and Postoperative Immunotherapy Response in Four Cases of Sarcomatoid Urothelial Carcinoma

Urothelial carcinoma with sarcomatoid differentiation (UCSD) is a rare and highly aggressive variant with a dismal prognosis. While immune checkpoint inhibitors (ICIs) have revolutionized treatment for advanced urothelial carcinoma, data on PD-L1 expression and its therapeutic implications in UCSD remain scarce. This case series describes four patients with upper tract UCSD who underwent radical surgery. Pathological examination confirmed tumors with diverse morphologies and, notably, high PD-L1 expression [Combined Positive Score (CPS) 30–90 or Tumor Proportion Score (TPS) 80%]. All patients received adjuvant ICI therapy (e.g., Toripalimab) based on their PD-L1 status. With a median follow-up of 18 months, all patients remain alive and disease-free, demonstrating favorable treatment responses. This series enriches the understanding of UCSD and highlights the potential therapeutic guidance value of PD-L1 testing in this aggressive subtype, providing a basis for individualized management.