Predictive role of PD-L1 expression in the response of renal Medullary carcinoma to PD-1 inhibition.

Background: Renal medullary carcinoma is one of the rarest malignancies arising from the kidney. Despite various aggressive therapeutic regimens, mortality remains significantly high (95%) with a median overall survival of 5 months. Furthermore, the scarcity of this malignancy renders randomized clinical trials impossible.