Clinical evaluation of medical and surgical complete responses in metastatic renal cell carcinoma treated with immune checkpoint inhibitor combination therapy.

[BACKGROUND] Achieving a complete response (CR) with immune checkpoint inhibitor (ICI)-based combination therapy is important in metastatic renal cell carcinoma (mRCC) systemic treatment. Surgical intervention for residual localized disease after ICI therapy may contribute to complete disease eradication and improved outcomes.

[METHODS] We retrospectively evaluated the clinical significance of medical CR (complete radiologic disappearance of all target lesions with ICI therapy) and surgical CR (radiographic CR after local surgery following ICI-based therapy) for patients with mRCC treated with ICI-based combination therapy. Patients were categorized into the IOIO (dual ICI therapy) and IOTKI (ICI + tyrosine kinase inhibitor therapy) groups.

[RESULTS] Of the 250 study patients, 107 and 143 received IOIO and IOTKI, respectively. The overall medical objective response and medical CR rates were 55.6% and 10.4%, respectively. Surgical CR and medical CR were achieved in 16.4% and 26.8% of individuals, respectively. Patients who achieved both medical CR and surgical CR experienced similarly favorable progression-free survival and overall survival (OS). Among those who achieved either surgical CR or medical CR, OS was longer in the IOIO group; however, no other significant intergroup differences were observed. Patients with primary tumors exhibited higher medical CR rates. No significant differences in treatment-related adverse events, treatment discontinuation, or steroid use between the medical CR and medical non-CR groups were observed.

[CONCLUSION] Approximately 25% of patients with mRCC achieved medical CR with ICI-based combination therapy. Treatment efficacy was comparable between the two regimen groups. A multidisciplinary strategy may lead to complete disease eradication for select patients.