1663 CHARACTERISTICS OF SMALL RENAL MASSES PROGRESSING TO METASTASES WHILE UNDER OBSERVATION: A POOLED ANALYSIS (2011)

You have accessJournal of UrologyKidney Cancer: Localized1 Apr 20111663 CHARACTERISTICS OF SMALL RENAL MASSES PROGRESSING TO METASTASES WHILE UNDER OBSERVATION: A POOLED ANALYSIS Marc Smaldone, Alexander Kutikov, Brian Egleston, Daniel Canter, Rosalia Viterbo, David Chen, Richard Greenberg, and Robert Uzzo Marc SmaldoneMarc Smaldone Philadelphia, PA More articles by this author , Alexander KutikovAlexander Kutikov Philadelphia, PA More articles by this author , Brian EglestonBrian Egleston Philadelphia, PA More articles by this author , Daniel CanterDaniel Canter Philadelphia, PA More articles by this author , Rosalia ViterboRosalia Viterbo Philadelphia, PA More articles by this author , David ChenDavid Chen Philadelphia, PA More articles by this author , Richard GreenbergRichard Greenberg Philadelphia, PA More articles by this author , and Robert UzzoRobert Uzzo Philadelphia, PA More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2011.02.1796AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Active surveillance (AS) for small renal masses (SRMs) has emerged as an alternative to surgical therapy in select patients. We conducted a systematic review and pooled analysis of studies investigating the natural history of SRMs under observation with an emphasis on tumor growth kinetics and clinical characteristics of lesions progressing to metastases. METHODS A MEDLINE search was performed to identify all clinical series reporting observation of suspected renal malignancies. We extracted demographic, clinical, and pathologic variables for SRMs progressing to metastases and those who did not. For studies reporting individual level data, comparisons were performed using Wilcoxon rank-sum tests. RESULTS A total of 18 series met screening criteria (all ≤level III evidence), of which individual level data was available for pooled analysis in 6 studies. Systematic review revealed 880 patients (936 SRMs) with mean initial tumor sizes ranging from 1.7–7.2 cm. These lesions demonstrated mean linear growth rates ranging from 0.1–0.7cm/year over observation periods ranging from 15–47.6 months. 32.5% of all lesions exhibited zero net growth over time; of this sub-cohort, no SRM progressed to metastasis. Eighteen cases (2.1%) progressing to metastasis were identified. Pooled analysis comparing progressors and non-progressors (N=282) revealed significant trends including increased age (75.1 vs. 66.6 years, p=0.026), initial tumor size (4.3 vs. 2.3 cm, p<0.0001) and volume (70.0 vs. 18.1cm3, p=0.0001), linear growth rate (0.8 vs. 0.3cm/yr, p=0.0004), and volumetric growth rate (27.4 vs. 6.5 cm3/yr, p<0.0001) in the progression cohort. CONCLUSIONS Our systematic review and pooled analysis support that the majority of SRMs under radiographic surveillance exhibit slow growth kinetics with a low short term risk of metastatic progression. However, while generally late events, a small proportion of SRMs under surveillance demonstrate evidence of progression, and the prediction of their natural growth history cannot be reliably determined by serial radiographic data alone. Utilizing available parameters, lesions that exhibit zero growth over time may represent a population appropriate for prolonged AS while positive growth rates self select for delayed intervention. In the absence of level I evidence, while it appears that observation of SRMs may be delayed without negative sequelae in patients with objectified competing risks, AS should not be considered an equivalent alternative to definitive surgical therapy in acceptable operative candidates. © 2011 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 185 Issue 4S April 2011 Page: e668 Advertisement Copyright & Permissions© 2011 by American Urological Association Education and Research, Inc.Metrics Author Information Marc Smaldone Philadelphia, PA More articles by this author Alexander Kutikov Philadelphia, PA More articles by this author Brian Egleston Philadelphia, PA More articles by this author Daniel Canter Philadelphia, PA More articles by this author Rosalia Viterbo Philadelphia, PA More articles by this author David Chen Philadelphia, PA More articles by this author Richard Greenberg Philadelphia, PA More articles by this author Robert Uzzo Philadelphia, PA More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...