Overall survival after stereotactic radiotherapy or surgical metastasectomy in oligometastatic renal cell carcinoma patients treated at two Swedish centres 2005–2014

Abstract Background and purpose Investigate effects of stereotactic radiotherapy (SRT) or surgical metastasectomy (SM) on overall survival (OS) in metastatic renal cell carcinoma (mRCC) in the era of targeted agents (TA). Material and methods mRCC patients ( n  = 117) treated with SRT ( n  = 57), SM ( n  = 30) or both modalities sequentially ( n  = 30) at two oncological centres in Sweden in 2005–2014 were retrospectively included. Median follow-up (mFU) was 63 months. Results A majority had clear cell histology, 1–3 metastases, and ECOG performance status of 0 or 1. Two thirds had intermediate or poor risk and 44% synchronous metastases. 65% received TA. SRT patients were more likely to have adverse risk profiles. Median OS was 51 months without significant differences between SRT and SM. ECOG 1 vs 0 (HR 2.9; CI 1.6–5.2; p p  = 0.03) and watchful waiting >18 months prior to treatment (HR 0.3; CI 0.2–0.6; p  = 0.001) were independently associated with OS. 15% of curatively treated patients ( n  = 60) were relapse-free with mFU of 87 months. Conclusions OS after SRT was comparable to SM and longer than expected considering patients with adverse risk profiles were common. Fit patients with non-brain metastases treated after an initial period of watchful waiting had the best prognosis.