[A Case of Long-Term Complete Remission by Pembrolizumab＋Axitinib, Cabozantinib for Papillary Renal Cell Carcinoma with Metastasis].

A 46-year-old woman presented to a local clinic complaining of discomfort in the right upper quadrant. Abdominal ultrasound revealed a right renal mass, and she was referred for further evaluation and treatment. Contrast-enhanced computed tomography showed a 54 mm right renal tumor and a 12 mm enlarged lymph node in the aortocaval region. She was diagnosed with right renal cell carcinoma, staged as cT1bN1M0. Laparoscopic right nephrectomy and lymph node dissection were performed, confirming the diagnosis of papillary renal cell carcinoma type 2, pT1bpN1. At nine months after surgery, she developed retroperitoneal recurrence with invasion of the second lumbar vertebra. Pembrolizumab combined with axitinib was initiated. After six months of treatment, she achieved a complete response with no detectable lesions. However, 17 months after the initiation of treatment, new multiple liver metastases appeared, and the response was classified as progressive disease. Second-line treatment with cabozantinib was started, leading to complete tumor regression after 16 months, with a complete response confirmed. She has maintained a complete response for 39 months since starting cabozantinib.