Active surveillance for small renal masses in younger patients
Reviewed by Jay Khastgir

Active surveillance (AS) is discussed as an option for renal masses <2cm in patients with significant competing risks for mortality. This multicentre data from the US seeks to fill an important gap in current guidelines for provision of this option in younger patients. Two hundred and forty-six patients aged ≤60 years were prospectively enrolled to the study and opted for primary intervention (67%) or AS (33%). Patients opting for AS had a smaller median tumour diameter (1.5cm). The authors report similar cancer-specific and overall survival at seven years (median 4.9 years) for patients treated with primary intervention or AS. The median growth rate was 0.09cm/year in the AS group; approximately 17% had a negative growth rate, 10% remained unchanged, 73% demonstrated growth. Twenty AS patients (29%) crossed over to delayed intervention, of whom 80% was for increased growth rate and 20% elected to do so. No patients developed metastatic disease and cancer-specific survival was 100%. Interpretation of this data requires careful evaluation regarding the role of renal biopsy and other parameters to characterise tumour biology in younger patients, whether linear tumour growth rate alone is an adequate indicator of progression risk, the optimal AS protocol, the role of novel imaging modalities and the impact of AS on mental health in younger individuals. Seventy-six percent of patients in the AS arm were in their 50s and 21% in their 40s, so the conclusions cannot be easily extrapolated to younger patients who may require biopsy and genetic evaluation. What this study highlights though, is that there exists a subset of indolent low risk tumours in young individuals who may be suitable for AS as an initial strategy.

Outcome of active surveillance for young patients with small renal masses: prospective data from the DISSRM registry.
Metcalf MR, Cheaib JG, Biles MJ, et al.
JOURNAL OF UROLOGY
2021;205(5):1286-93.