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Active surveillance is emerging as a safe and effective strategy for the management of small renal masses (4 cm or less). We characterized the growth rate and its pertinence to clinical outcomes in a prospective multi-institutional study of patients with small renal masses.

Materials and Methods:

Since 2009, the DISSRM (Delayed Intervention and Surveillance for Small Renal Masses) prospective, multi-institutional registry of patients with small renal masses has enrolled patients who elect primary intervention or active surveillance. Patients who elect active surveillance received regularly scheduled imaging and those with 3 or more followup images were included in the current study to evaluate growth rates.


We evaluated 318 patients who elected active surveillance, of whom 271 (85.2%) had 3 or more followup images available with a median imaging followup of 1.83 years. The overall mean ± SD small renal mass growth rate was 0.09 ± 1.51 cm per year (median 0.09) with no variables demonstrating statistically significant associations. The growth rate and variability decreased with longer followup (0.54 and 0.07 cm per year at less than 6 months and greater than 1 year, respectively). No patients had metastatic disease or died of kidney cancer. No statistically significant difference was noted in the growth rate in patients with biopsy demonstrated renal cell carcinoma or in those who died.


Small renal mass growth kinetics are highly variable early on active surveillance with growth rates and variability decreasing with time. Early in active surveillance, especially during the initial 6 to 12 months, the growth rate is variable and does not reliably predict death or adverse pathological features in the patient subset with available pathology findings. An elevated growth rate may indicate the need for further assessment with imaging or consideration of biopsy prior to progressing to treatment. Additional followup will inform the best clinical pathway for elevated growth rates.


  • 1 National Cancer Institute Surveillance, Epidemiology and End Results Program: Cancer Stat Facts: Kidney and Renal Pelvis Cancer. Updated 2017. Available at Accessed February 15, 2017. Google Scholar
  • 2 : Epidemiology and risk factors for kidney cancer. Nat Rev Urol2010; 7: 245. Google Scholar
  • 3 : The evolving presentation of renal carcinoma in the United States: trends from the Surveillance, Epidemiology, and End Results Program. J Urol2006; 176: 2397. LinkGoogle Scholar
  • 4 : Five-year analysis of a multi-institutional prospective clinical trial of delayed intervention and surveillance for small renal masses: the DISSRM registry. Eur Urol2015; 68: 408. Google Scholar
  • 5 : Active surveillance of small renal masses: progression patterns of early stage kidney cancer. Eur Urol2011; 60: 39. Google Scholar
  • 6 : Small renal masses progressing to metastases under active surveillance: a systematic review and pooled analysis. Cancer2012; 118: 997. Google Scholar
  • 7 : Distribution of renal tumor growth rates determined by using serial volumetric CT measurements. Radiology2009; 250: 137. Google Scholar
  • 8 : Growth pattern of renal cell carcinoma (RCC) in patients with delayed surgical intervention. J Cancer Res Clin Oncol2012; 138: 269. Google Scholar
  • 9 : Growth pattern of clear cell renal cell carcinoma in patients with delayed surgical intervention: fast growth rate correlates with high grade and may result in poor prognosis. Biomed Res Int2015; 2015: 598134. Google Scholar
  • 10 : Most renal oncocytomas appear to grow: observations of tumor kinetics with active surveillance. J Urol2011; 186: 1218. LinkGoogle Scholar
  • 11 : Active surveillance for small renal masses. Rev Urol2012; 14: 13. Google Scholar
  • 12 : Growth kinetics of renal masses: analysis of a prospective cohort of patients undergoing active surveillance. Eur Urol2011; 59: 863. Google Scholar
  • 13 : Growth kinetics of small renal masses: a prospective analysis from the Renal Cell Carcinoma Consortium of Canada. Can Urol Assoc J2014; 8: 24. Google Scholar
  • 14 : Diagnostic accuracy and risks of biopsy in the diagnosis of a renal mass suspicious for localized renal cell carcinoma: systematic review of the literature. J Urol2016; 195: 1340. LinkGoogle Scholar
  • 15 : Kidney cancer: undertreatment of small renal masses by overuse of biopsy. Nat Rev Urol2016; 13: 701. Google Scholar
  • 16 : The natural history of observed enhancing renal masses: meta-analysis and review of the world literature. J Urol2006; 175: 425. LinkGoogle Scholar
  • 17 : Distinguishing malignant and benign renal masses with composite models and nomograms: a systematic review and meta-analysis of clinically localized renal masses suspicious for malignancy. Cancer2016; 122: 3267. Google Scholar
  • 18 : Grade heterogeneity in small renal masses: potential implications for renal mass biopsy. J Urol2015; 193: 36. LinkGoogle Scholar
  • 19 : Balancing cardiovascular (CV) and cancer death among patients with small renal masses: modification by CV risk. BJU Int2015; 115: 58. Google Scholar
  • 20 : Management of renal masses and localized renal cancer: systematic review and meta-analysis. J Urol2016; 196: 989. LinkGoogle Scholar
  • 21 : Variability in size measurement of renal masses smaller than 4 cm on computerized tomography. J Urol2006; 176: 2386. LinkGoogle Scholar
  • 22 : Comparison of radiographical imaging modalities for measuring the diameter of renal masses: is there a sizeable difference?. BJU Int2011; 108: E232. Google Scholar
  • 23 : Is ultrasound imaging inferior to computed tomography or magnetic resonance imaging in evaluating renal mass size?. Urology2012; 79: 28. Google Scholar