A systematic review of the quality of evidence of ablative therapy for small renal masses

Purpose: We critically assessed the methodological and reporting quality of published studies of ablative techniques for small renal masses. Materials and Methods: We performed a systematic PubMed® and EMBASE® literature search from January 1966 to March 2010 to identify all full text, original research publications on ablative therapy for renal masses. Six reviewers working independently in 3 teams performed duplicate data abstraction using Strengthening the Reporting of Observational Studies in Epidemiology criteria, which were pilot tested in a separate sample. Results: A total of 117 original research publications published in a 15-year period (1995 to 2009) met eligibility criteria. No randomized, controlled trials were identified. All studies were observational and 88.9% had 1 arm with no comparison group. Median sample size was 18 patients (IQR 5.5, 40.0) and 53.8% of studies included 20 or fewer patients. Median followup was 14.0 months (IQR 8.0, 23.8) and only 19.7% of studies had an average followup of greater than 24 months. Of the studies 20.5% mentioned the number of operators involved and only 6.0% provided information on their experience level. Of the studies 66.7% addressed the recurrence rate. Disease specific and overall survival was reported in only 15.4% and 16.2% of studies, respectively. Conclusions: The published literature on the therapeutic efficacy of ablative therapy for renal masses is largely limited to uncontrolled, 1-arm observational studies. In the absence of higher quality evidence ablative therapy outside research studies should be limited to select patients who are not candidates for surgical intervention.