Maintaining the same systemic therapy after stereotactic radiosurgery (SRS) to treat central nervous system (CNS) or spinal lesions does not affect clinical outcomes among patients with metastatic renal cell carcinoma (mRCC), according to a study published in Clinical Genitourinary Cancer.1
Treatment strategies in oligoprogression among patients with mRCC include switching systemic therapies or applying SRS while maintaining the same systemic therapy. How switching or continuing the same systemic therapy affects clinical outcomes post-SRS, however, requires further study.
For this retrospective analysis, researchers assessed the outcomes of 95 patients with mRCC who had had undergone SRS to the CNS or spine during systemic treatment. Participants were stratified into groups according to if they maintained (STAY) or switched systemic therapy (SWITCH) after SRS, or experienced disease progression outside the SRS sites and switched systemic therapy (PD-SYS).
SRS led to local control in 85% of patients; the most commonly used systemic therapies were anti-VEGF (67%), rapamycin (14%), and PD-1/PD-L1 inhibitors (9%).
After a median follow-up of 28.8 months, the median treatment duration for the STAY group was 5.2 months (95% CI, 3.5-6.9) compared with 5.0 months (95% CI, 4.3-5.7) for the SWITCH group (P = .549); the median duration of treatment for the PD-SYS group was 3.1 months (95% CI; 1.7-4.5) (P = .07, when compared with the other groups).
The median overall survival was 24.2 and 27.1 months among the STAY and SWITCH groups, respectively (P = .381); median overall survival was significantly longer for both the STAY and SWITCH groups compared with the PD-SYS group (P = .025).
Evidence from the study demonstrates that maintaining the same systemic therapy with oligoprogression is reasonable, and is not negatively affected by SRS. The authors concluded that “the choice to stay with or switch a treatment should be individualized by the tolerance of the existing regimen, the presence of progressive disease outside SRS sites, and patient access to subsequent therapies.”
- Barata PC, Mendiratta P, Kotecha R, et al. Effect of switching systemic treatment after stereotactic radiosurgery for oligoprogressive, metastatic renal cell carcinoma [published online August 16, 2018]. Clin Genitourin Cancer. doi: 10.1016/j.clgc.2018.07.018