Efficacy of Enfortumab Vedotin After Chemotherapy With Anti-programmed Death-Ligand 1 (PD-L1) Maintenance Treatment in a Clear Cell Variant of Invasive Urothelial Carcinoma of the Renal Pelvis: A Case Report.

Among upper urinary tract urothelial carcinoma (UUTUC) cases, there are few reports of the clear cell variant. Systemic chemotherapy will be given according to the usual treatment for urothelial cancer unless lymph nodes or organ metastases make surgical treatment inappropriate. Here, we report a clear cell variant of UUTUC of the left renal pelvis with aortic lymph node metastasis. The patient in this case was treated with systemic chemotherapy, anti-programmed death-ligand 1 (PD-L1) maintenance treatment, radiation therapy, and enfortumab vedotin (EV) therapy. To determine which of the treatments contributed to the therapeutic effect, immunostaining was used. The results indicated that Nectin-4 was expressed in clear cell variant tissues, while programmed cell death protein 1 (PD-1) and PD-L1 expression levels were weak in these tissues. The patient maintained complete remission with these treatments. Two years after the initial treatment, the patient was still alive with no progression or metastasis.