ASTRO 2017: Can SABR Provide an Alternative to Surgery for Primary Renal Tumors in Metastatic Kidney Cancer?
Rohann Correa, MD, PhD, of the London Regional Cancer Program, Ontario, Canada, and colleagues suggest that stereotactic ablative radiation therapy (SABR) may provide a safe and effective alternative to cytoreductive nephrectomy in patients with primary tumors in the setting of metastatic renal cell carcinoma who are unable or unwilling to undergo surgery. Results from their phase I study, which evaluated toxicity, renal function, and quality of life following SABR in this patient population, were presented at the 2017 American Society for Radiation Oncology (ASTRO) Annual Meeting (Abstract 331).
A total of 12 patients were enrolled in successive dose cohorts receiving up to 35 Gy in 5 fractions. Patients who underwent SABR had a median reduction in tumor size of –17.3%, although systemic disease progression occurred in all patients. After a median follow-up of 22 months, the overall survival was 6.7 months. Most adverse events were grade 2 or under.
According to the investigators, dose escalation up to 35 Gy was achieved successfully in patients with metastatic kidney disease; toxicity was minimal, renal function was preserved, and quality of life remained stable, they noted. With recent evidence indicating radiation may stimulate antitumor immunity, Dr. Correa and colleagues are planning to combine SABR with immune checkpoint inhibition in an attempt to identify immunologic biomarkers of response.