Effect of Switching Systemic Treatment After Stereotactic Radiosurgery for Oligoprogressive, Metastatic Renal Cell Carcinoma.

Background: We assessed the clinical outcomes of patients with oligoprogressive renal cell carcinoma (mRCC) treated with stereotactic radiosurgery (SRS), stratified by changing or continuing systemic treatment.
Patients and Methods: Ninety-five consecutive patients with clear cell mRCC who had undergone SRS to the central nervous system (CNS) or spine during systemic treatment were divided into 3 cohorts: those who continued the same systemic therapy (STAY), those who changed systemic treatment after SRS (SWITCH), and patients with progression outside the SRS sites, who also changed systemic treatment (PD-SYS). The primary outcome was treatment duration after SRS, defined as the interval between SRS and discontinuation of the current systemic therapy for the STAY group and discontinuation of the first subsequent therapy in the SWITCH and PD-SYS groups.
Results: Local control with SRS was achieved in 85% of the patients. The most common systemic treatment at SRS included anti-vascular endothelial growth factor (67%), mammalian target of rapamycin (14%), and programmed cell death protein 1 inhibitors (9%). The median treatment duration for the STAY group was 5.2 months (95% confidence interval [CI], 3.5-6.9) compared with 5.0 months (95% CI, 4.3-5.7) for the SWITCH group (P = .549) and 3.1 months (95% CI, 1.7-4.5) for the PD-SYS group (P = .07, compared with all other patients). No difference in median overall survival was found for the STAY and SWITCH groups (24.2 vs. 27.1 months; P = .381) but was significantly longer than that for the PD-SYS group (P = .025).
Conclusion: The decision to continue the same systemic therapy at SRS to treat CNS or spinal lesions did not compromise the clinical outcomes of patients with oligoprogressive mRCC.
(Copyright © 2018 Elsevier Inc. All rights reserved.)