Complete Response to Sorafenib Rechallenge in a Patientwith Metastatic Renal Cell Carcinoma

A 79-year-old Japanese man underwent a medical examination for hoarseness. Computed tomography revealed a left renal tumor,and radical nephrectomy was performed. The tumor was a clear cell carcinoma. Fourteen months after the operation, the tumor hadmetastasized to the spleen, right lung, and retroperitoneal lymph nodes. We initiated molecular targeted therapy sequentially withsorafenib, sunitinib, and axitinib and then conducted a rechallenge with sorafenib. His metastatic lesions had completely vanished 5months after initiation of the rechallenge. Ten months after the rechallenge, lumbar vertebral body metastasis appeared. However,we consider that the sorafenib rechallenge was effective because of the very slow growth of the metastatic lesion, with no othermetastasis for 30 months, at the time of writing this report. Approximately 7 years after the first local recurrence, he remained alive,with relatively normal daily functioning.