ORLANDO, FL USA (UroToday.com) - Patients with small renal masses (SRM, ≤ 4cm) can be monitored by active surveillance (AS), but implications of growth rate (GR) in AS patients have yet to be fully elucidated. The authors hypothesize that variability of measurements on radiographic studies can lead to worrisome GR over short time intervals and should be tempered with the knowledge that GR of SRM are slow over extended time periods. Therefore they investigated growth patterns of patients with small renal masses.
In this prospective study, patients were enrolled following consultation and choice of AS or intervention. Those electing AS followed an imaging protocol every 4-6 months for the first 2 years, then every 6-12 months for the next 3 years. Progression was defined as GR > 0.5cm/year, at which point intervention is recommended. GRs were calculated based on changes in the largest tumor dimension (cm) per year.
A total of 177 patients undergoing AS were enrolled in the study. Mean GR for the entire cohort was 0.19 cm/year with a significantly higher GR (0.52) within the first 182 days of AS (p=0.02). The percent of patients with GR progression was higher within the first 6 months of AS (p < 0.001). Of 21 patients electing to crossover, only 8 did so for elevated GR.
The study group showed that in patients with SRM undergoing AS, GR is slow on average (0.19cm/year). Dr. Readal pointed out that GR may be exaggerated on the first AS image based on the fact that small changes in growth over a short interval can produce rapid GR.
In conclusion clinicians should use early growth kinetics cautiously and temper their recommendation for intervention in the initial phase of AS to prevent over treatment.
Presented by Nathaniel Readal, 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