Risk prediction in the management of small renal masses

Small renal masses (SRMs) are frequently encountered due to the ubiquitous use of abdominal cross-sectional imaging. Enhanced risk prediction in the management of SRMs would allow for a more informed decision of which, if any, patients would benefit from the available intervention modalities.

Data suggest that a substantial proportion of SRMs are benign and that a significant proportion demonstrate indolent clinical behavior, leading to increased implementation of active surveillance strategies. Extirpative treatment of SRMs may be associated with worse outcomes, particularly in the elderly and infirm. Patient characteristics, including advanced age and comorbidity, and tumor anatomy are being increasingly recognized as having significant prognostic importance in terms of which type of treatment to offer. Further, a recent renewed interest in renal mass biopsy for risk stratification in SRMs has occurred as tumor size, radiographic characteristics, and growth kinetics are limited in their predictive capacity.

Within the last decade, the reference standard treatment of SRMs evolved from radical nephrectomy to nephron-sparing approaches. This evolution continues, as we learn more about the complex interplay between patient and tumor characteristics and, as outcomes data mature, to ablative therapies and active surveillance.