Research progress on PD-1 and PD-L1 inhibitors in the treatment of metastatic urothelial carcinoma.

Urothelial carcinoma (UC) is a very common malignant tumor. In the past few decades, platinum-based chemotherapy has been regarded as the standard recommended regimen for patients with metastatic urothelial carcinoma (mUC) who can receive either cisplatin or carboplatin. The emergence of immune checkpoint inhibitors (ICIs) brought some hope for possible treatments for mUC patients who were unfit for platinum therapy.