SIU 2017: Growth Kinetics of Small Renal Mass: Initial Analysis of Korean Active Surveillance Registry

Lisbon, Portugal ( While active surveillance for small solid renal masses has been slowly gaining acceptance, different populations continue to assess the feasibility and safety of the management in their own unique populations. In this manuscript, the authors assess safety and natural history of AS of SRMs in their institute in Korea.

In this prospective study from 2010 to 2016, 37 patients with SRMs <3 cm were enrolled. While CT and MRI axial imaging were used for initial diagnosis, patients were followed with CT, ultrasound, and Chest CT at q6 month intervals. After 2 years of stability, follow-up was stretched to annually. Triggers for intervention (and classification of progression) were growth rate > 0.5 cm/year, size > 4 cm, or if clinical progression was noted. 

Table 1 demonstrates basic demographics. 6 of 37 patients progressed. Mean follow-up was 27.8 months. Mean diameter at diagnosis was 1.8 cm. Patients who progressed tended to have faster mean growth rate (9.6 mm/year vs. 0.9 mm/year) and higher rate of biopsy (83% vs. 22.6%), but were otherwise very similar. Of note, approximately 20% of patients in the AS cohort without progression were cystic in nature. All those that progressed were solid. The primary trigger for “progression” was growth rate. Of the 6 patients, 3 wished to stay on AS – the other 3 had partial nephrectomy, but there was no review of the final pathology. There was no other clinical progression or metastases. 

The early results of this Korean group are consistent with other series. However, they had stricter criteria for progression. Active Surveillance and even renal biopsy can probably be used more regularly for these small renal masses. We hope they will continue to use AS and will loosen their definition of progression and reduce the aggressiveness of their follow-up imaging.

Presented by: Sung-Woo Park, South Korea 

Written by: Thenappan Chandrasekar, MD, Clinical Fellow, University of Toronto, twitter: @tchandra_uromd, at the 37th Congress of Société Internationale d’Urologie - October 19-22, 2017- Lisbon, Portugal