ORLANDO, FL USA (UroToday.com) - Active surveillance (AS) for patients with a small renal mass (SRM) is a viable alternative to surgery due to the slow tumor growth, low risk of metastasis, and presumed retention of renal function. The research group compared renal function for patients on AS with patients undergoing extirpative modalities. They also correlated tumor growth rate with renal functional decline in AS patients.
Since January 2009, patients with SRMs ≤ 4cm were prospectively enrolled in the multi-institutional DISSRM (Delayed Intervention and Surveillance for Small Renal Masses) Registry, either into AS or intervention arms. Those electing AS followed an imaging protocol. Growth rates and glomerular filtration rate (GFR) were calculated. GFR change was calculated from the first value for surveillance patients or the pre-operative value for intervention patients, to the most recent value. Linear regression was used to determine the effects of study arm and growth rate on GFR, while controlling for the impact of demographics, comorbidities, and tumor histology.
Dr. Danzig pointed out that there was no significant difference in average GFR decline between the 66 partial nephrectomy (PN) patients and the 67 AS patients (1.9 vs 0.5, p=0.270). In contrast, there was a significantly greater decline in the 15 radical nephrectomy (RN) patients compared to the AS patients (9.2 vs 0.5, p=0.001). On regression analysis while controlling for comorbidities, GFR was again found to decline faster in RN (p=0.016) but not in PN (p=0.778) patients compared to AS patients.
The authors conclude that AS for the small renal mass yields equivalent preservation of GFR when compared to PN, while both modalities are superior to radical nephrectomy. Preservation of renal function during AS is unaffected by growth rate. This should be considered when planning treatment options.
Presented by Matthew Danzig, MD at the American Urological Association (AUA) Annual Meeting - May 16 - 21, 2014 - Orlando, Florida USA
New York, NY USA
Written by Achim Lusch, MD, University of California (Irvine), and medical writer for UroToday.com