Effectiveness of pembrolizumab in therapy of sarcomatoid variant of metastatic urothelial carcinoma. Clinical case

Sarcomatoid variant of urothelial carcinoma is a rare histological subtype: it is diagnosed in 0.1–0.3 % of all neoplasms of the bladder. The standard 1st line therapy for all types of advanced urothelial carcinoma is chemotherapy which does not necessarily allow to achieve the best or complete responses, especially in the presence of sarcomatoid differentiation. High programmed cell death-ligand 1 (PD-L1) expression in this morphological subtype allows to assume better results of immunotherapy compared to chemotherapy. However, a large number of observations is necessary to confirm this hypothesis and suggest pembrolizumab immunotherapy as a standard 1st line therapy for metastatic urothelial carcinoma with sarcomatoid differentiation.