Pathological Complete Response of Metastatic Clear Cell Renal Carcinoma with Pembrolizumab and Axitinib: A Case Report and Review of Literature

Abstract The role of cytoreductive nephrectomy has become unclear since the introduction of immunotherapy which is now the backbone of the treatment for metastatic renal cell carcinoma. Different combinations are used based on the prognosis. Achieving a complete response would be ideal and includes radiographic disappearance of lesions. However, there have been a few reported cases of pathological complete response with persistent radiographic evidence of cancer. The authors report a case of pathological complete response despite persistent radiographic evidence of residual disease in a patient with metastatic renal cell carcinoma treated with pembrolizumab and axitinib. The patient subsequently underwent cytoreductive nephrectomy after the 13th dose of pembrolizumab. The resected mass consisted of scar tissue with no viable tumor cells seen on pathology but only scar tissue. This case reveals that persistent radiographic evidence of the tumor may be explained by scar tissue, challenging the role of cytoreductive nephrectomy in the era of immunotherapy.