Active Surveillance of Small Renal Masses: A Systematic Review

BACKGROUND: Our goal is to review current literature regarding active surveillance (AS) of small renal masses (SRMs) and identify trends in survival outcomes, factors that predict the need for further intervention, and quality of life (QOL). METHODS: We performed a comprehensive literature search in PubMed and EMBASE and identified 194 articles. A narrative summary was performed in lieu of a meta-analysis due to the heterogeneity of selected studies. RESULTS: Seventeen articles were chosen to be featured in this review. Growth rate (GR) was not an accurate predictor of malignancy, although it was the characteristic most commonly used to trigger delayed intervention (DI). The mean 5-year overall survival (OS) of all studies was 73.6% ±1.7% for AS groups. The combined cancer specific survival (CSS) for AS is 97.1% ±0.6%, compared to 98.6% ±0.4% for the primary intervention (PI) groups, (p = 0.038). CONCLUSIONS: Short and intermediate-term data demonstrate that AS with the option for DI is a management approach whose efficacy (in terms of CSS) approaches that of PI at 5 years, is cost effective, and prevents overtreatment, especially in patients with significant comorbidities.