Assistant Professor of Neurosurgery and Orthopaedics Vanderbilt University Medical Center Nashville, Tennessee, United States
Introduction: While novel targeted systemic therapy agents have lengthened survival in patients with metastatic renal cell carcinoma (RCC), it remains unknown how targeted systemic therapy impacts outcomes after spine surgery. In patients undergoing metastatic spine surgery for RCC, we sought to: 1) describe patterns of postoperative targeted systemic therapy, 2) compare perioperative outcomes among patients receiving versus not receiving targeted systemic therapy, and 3) evaluate the impact of targeted systemic therapy on overall survival (OS) and local recurrence (LR).
Methods: A single-institution, retrospective study of patients undergoing metastatic spine surgery for RCC from 2010-21 was undertaken. Postoperative treatment groups were divided into: radiotherapy (RT) alone, targeted systemic therapy alone, dual therapy consisting of RT and targeted systemic therapy, and neither therapy. Multivariable Cox regression controlled for age, race, sex, insurance, and preoperative targeted systemic therapy.
Results: Forty-nine patients underwent spine surgery for RCC with a median (IQR) follow-up of 542(200-837) days. Postoperatively, 4(8%) patients received RT alone, 19(38.8%) targeted systemic therapy alone, 12(24.5%) dual therapy, and 13(28.6%) neither. All groups were similar in demographics, preoperative Karnofsky Performance Score (KPS)(p=0.372) and tumor size(p=0.413). Among the four groups, no difference was found regarding readmissions (p=0.884), complications(p=0.272), KPS(p=0.466), and Modified McCormick Scale (MMS)(p=0.980) at last follow-up. Higher one-year OS was found in patients undergoing dual therapy (83.3%) compared to other groups(p=0.013). OS was significantly longer in patients with dual therapy compared to targeted systemic therapy alone, RT alone, and neither therapy(log-rank;p=0.010). Multivariate Cox regression(HR=0.08,95%CI=0.02-0.31,p < 0.001) showed longer OS for patients receiving dual therapy compared to other therapies. However, a similar time to LR was found between all four groups(log-rank;p=0.190).
Conclusion : In patients undergoing spine surgery for metastatic RCC, postoperative dual therapy consisting of targeted systemic therapy and radiation therapy demonstrated significantly higher one-year and overall survival compared to targeted systemic therapy alone, RT alone, and neither therapy.
