Concurrent sunitinib and stereotactic body radiotherapy for patients with oligometastases

Preliminary results demonstrated that concurrent sunitinib and stereotactic body radiation therapy (SBRT) is an active regimen for metastases limited in number and extent. This analysis was conducted to determine the long-term survival and cancer control outcomes for this novel regimen. Forty-six patients with oligometastases, defined as five or fewer clinical detectable metastases from any primary site, were treated on a phase I/II trial from February 2007 to September 2010. The majority of patients were treated with 37.5 mg sunitinib (days 1-28) and SBRT 50 Gy (days 8-12 and 15-19) and maintenance sunitinib was used in 39 % of patients. Median follow up for surviving patients is 3.6 years. The 4-year estimates for local control, distant control, progression-free and overall survival were 75 %, 40 %, 34 % and 29 %, respectively. At last follow-up, 26 % of patients were alive without evidence of disease, 7 % were alive with distant metastases, 48 % died from distant metastases, 2 % died from local progression, 13 % died from comorbid illness, and 4 % died from treatment-related toxicities. Patients with kidney and prostate primary tumors were associated with a significantly improved overall survival (hazard ratio = 0.25, p = 0.04). Concurrent sunitinib and SBRT is a promising approach for the treatment of oligometastases and further study of this novel combination is warranted.