Small Renal Masses Initially Managed Using Active Surveillance: Results From a Retrospective Study With Long-Term Follow-Up

BackgroundThe purpose of this study was to provide outcomes of patients managed using active surveillance (AS) for small renal masses (SRMs).Patients and MethodsWe retrospectively reviewed data of 62 patients diagnosed with 64 contrast enhancing SRMs suspicious for renal cell carcinoma. We evaluated the differences between patients who remained on AS and those who underwent delayed surgical intervention.ResultsThe mean age of patients was 75 years and the mean follow-up was 91.5 months. The median tumor size and the median estimated tumor volume were 2.6 cm and 8.7 cm3, respectively. The median linear growth rate and the median volumetric growth rate were 0.7 cm/y and 8.8 cm3/y, respectively. The mean linear and volumetric growth rates of the group of patients who underwent surgery was higher than in those who remained on surveillance (1.9 vs. 0.4 cm/y and 16.1 vs. 4.6 cm3/y, respectively; P < .001).ConclusionMost SRMs show an indolent course, with low metastatic potential. Faster linear and volumetric growth rates could be the expression of malignant disease, thus suggesting the need for a delayed surgical intervention. AS is a reasonable option for the management of SRMs in properly selected patients with low life expectancy.