Sustained complete remission with third-line nivolumab in advanced renal cell carcinoma: a case report

BACKGROUND: Renal cell carcinoma is a challenging malignancy that often necessitates advanced systemic therapies. Immunotherapy with checkpoint inhibitors has emerged as a cornerstone for managing advanced renal cell carcinoma. This case highlights the clinical course, treatment response, and management of complications in a patient with advanced renal cell carcinoma treated with immunotherapy. CASE PRESENTATION: A 51-year-old white male patient presented with dizziness, leading to a diagnosis of advanced renal cell carcinoma involving a large left renal mass, pulmonary metastases, and retroperitoneal lymphadenopathy. After radical nephrectomy in 2016, histopathology confirmed T3a clear cell carcinoma with vascular invasion. Initial systemic treatment included targeted therapy with sunitinib, followed by axitinib owing to disease progression. Nivolumab, a programmed death-1 inhibitor, became available in Hungary in 2018 and was initiated as third-line therapy in mid-2018. The patient has remained disease-free without any therapy for the past 27 months, with follow-up imaging through September 2025 confirming sustained complete remission first documented in October 2020, amounting to nearly 5 years of continuous complete remission. The patient experienced manageable immune-related adverse events, including nephritis and colitis, which were treated with corticosteroid therapy. Routine imaging and clinical assessments confirmed no evidence of recurrence as of September 2025. This case underscores the efficacy and durability of immune checkpoint inhibitors in advanced renal cell carcinoma. CONCLUSION: This case exemplifies the long-term benefit of immunotherapy in advanced renal cell carcinoma, emphasizing the importance of vigilant monitoring for immune-related adverse events, sustained follow-up, and the potential for extended therapy-free remission.