Intra-arterial infusion of bevacizumab for the treatment of peritoneal metastatic high-grade renal cell carcinoma: a case report.

Background: Metastatic renal cell carcinoma (mRCC) is a common type of urologic malignancy with limited systemic treatment, especially for extensive metastatic lesions in the peritoneum and greater omentum. Case report: A 35-year-old male patient was admitted to the hospital with left lumbar pain, leading to the discovery of left renal mass. He subsequently underwent a nephrectomy, with postoperative pathology confirming RCC. Following surgery, he received three cycles of interleukin-2 therapy. Within 5 months of nephrectomy, related examinations confirmed tumor recurrence and metastasis, and palliative surgery was performed. Postoperative pathology confirmed high-grade RCC, diagnosed as stage IV with pancreatic, adrenal, and splenic metastases. The patient then underwent first-line treatment with ICI (Immune Checkpoint Inhibitors) in combination with pezopanib for 9 months before progressing and then changing to second-line treatment with ICI in combination with axitinib for 2 months before progressing again. The patient was subsequently screened for clinical studies and rapidly progressed to extensive abdominal metastases after 1 month. The patient was then treated with bevacizumab abdominal artery perfusion embolization and achieved partial remission. Subsequent systemic therapy was changed to everolimus combined with voronib targeted therapy until now, and the lesion has continued to shrink on multiple follow-ups in between. Conclusion: Abdominal arterial infusion of bevacizumab embolization provides a feasible local treatment option for peritoneal metastases in stage IV RCC, warranting further clinical exploration.