Survival After Surgery for Renal Cell Carcinoma Metastatic to the Spine: Impact of Modern Systemic Therapies on Outcomes

Background Modern medical management of metastatic renal cell carcinoma (RCC) includes therapies targeting tyrosine kinases, growth pathways (mammalian target of rapamycin (mTOR)), and immune checkpoints. Objective To test our hypothesis that patients with spinal metastases would benefit from postoperative systemic therapy despite presenting with disease that, in many cases, was resistant to prior systemic therapy. Methods This is an Institutional Review Board-approved clinical retrospective cohort analysis. A sample of adult patients with RCC metastatic to the spine who underwent operative intervention between January 2010 and December 2017 at 2 large academic medical centers was used in this study. Results We identified 78 patients with metastatic RCC in whom instrumented stabilization was performed in 79% and postoperative stereotactic radiosurgery was performed in 41% of patients. Of patients presenting with weakness or myelopathy, 93% noted postoperative improvement and 78% reported improvement in radicular and axial paraspinal pain severity. Increased overall survival (OS) (913 d (95% CI: 633-1975 d, n = 49) vs 222 d (95% CI: 143-1005 d, n = 29), P = .003) following surgery was noted in patients who received postoperative systemic therapy a median of 80 d (interquartile range 48-227 d) following the surgical intervention. Conclusion Postoperative outcomes and palliation of symptoms for metastatic RCC without targeted therapies in this cohort are similar to those reported in earlier series prior to the adoption of these systemic therapies. We observed a significantly longer OS among patients who received modern systemic therapies postoperatively. These findings have implications for the preoperative evaluation of patients with systemic disease who may have been deemed poor surgical candidates prior to the availability of these systemic therapies.