Active Surveillance for Small Renal Masses

With greater awareness of indolence underlying small renal masses (SRM ≤ 4 cm) and the morbidity of invasive treatment, active surveillance for SRM patients is being increasingly utilized on an international level. This synopsis summarizes the 2022 review and expert opinion recommendations provided to the International Consultation of Urological Diseases (ICUD) by 10 urologists from high-volume active surveillance practices at international centers. Topics reviewed include SRM biology and clinical behavior, current national and international guidelines for active surveillance of SRM patients, active surveillance utilization patterns and barriers to implementation, outcomes and limitations of the active surveillance literature, criteria for active surveillance patient selection, protocols for active surveillance management including frequency/modality of imaging and the role of renal tumor biopsy, triggers for delayed intervention during active surveillance including tumor factors and patient factors, and pathological outcomes of delayed intervention. We conclude that despite limitations of the current literature, active surveillance is a safe initial management strategy for many SRM patients. The slow growth and low metastatic potential of SRMs, combined with no evidence to suggest oncologic compromise with delay to treatment, should provide confidence to both patients and providers who are considering active surveillance. Future research for prioritization should include characterization of long-term active surveillance outcomes including rates of metastasis and delayed intervention, standardization of objective tumor progression criteria for triggering delayed intervention, and further delineation of the role for active surveillance in young and healthy patients.