title: Predicting growth of solid renal masses under active surveillance.
abstract: OBJECTIVE
  The natural history and growth rates of untreated solid enhancing renal tumors is being defined through active surveillance series. Serial radiographic evaluation of patients who are not surgical candidates or refuse surgical treatment provides an opportunity to characterize the growth of untreated enhancing renal tumors. Here we evaluate factors that may help predict radiographic growth during observation.
  
  
  METHODS
  We reviewed our renal cancer database for enhancing renal masses that were radiographically observed for a period of at least 12 months. Variables examined included patient age, gender, lesion size on presentation, radiographic tumor characteristics, duration of active surveillance, linear growth rate, surgical pathology, development of new renal tumors, and stage progression.
  
  
  RESULTS
  One hundred nine patients with 124 sporadic enhancing renal tumors were identified undergoing a period of active surveillance of at least 12 months. Median patient age was 73 years (mean 69.8, range 35-87); 72% (78/109) of patients were males. Median duration of active surveillance was 26 months (mean 33.4, range 12-156). Multifocal disease was present in 9% (10/109) of patients on presentation, accounting for 20% (25/124) of all tumors. Tumor size on presentation was a median of 2.0 cm (mean 2.61, range 0.4-12.0). Overall median tumor growth rate was 0.21 cm/y (mean 0.28, range 1.4-2.47). Observed linear growth rates were independent of patient age, gender, tumor size on presentation, multifocality, and radiographic characteristics (solid versus cystic), P > 0.05. Of the patients initiating a period of active surveillance 36% (39/109) eventually underwent definitive therapy. Malignant pathology was present in 90% (35/39) of patients undergoing treatment. In patients continuing active surveillance [64% (70/109)], 2.9% (2/70) developed de novo renal lesions and 1.4% (1/70) developed metastatic disease.
  
  
  CONCLUSIONS
  Currently, no clinical predictors of tumor growth or disease progression have been identified, although, the risk of developing progressive disease over the short term appears low. Clinical and molecular markers of disease progression are needed prior to offering active surveillance to otherwise acceptable surgical candidates.
authors.affiliation: Department of Urologic Oncology, Fox Chase Cancer Center, Philadelphia, PA 19111, USA.
authors.forename: Paul L
authors.initials: PL
authors.lastname: Crispen
authors.forename: Yu-Ning
authors.initials: YN
authors.lastname: Wong
authors.forename: Richard E
authors.initials: RE
authors.lastname: Greenberg
authors.forename: David Y T
authors.initials: DY
authors.lastname: Chen
authors.forename: Robert G
authors.initials: RG
authors.lastname: Uzzo
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002292:Carcinoma, Renal Cell / Q000000981:diagnostic imaging* / Q000473:pathology*; D018450:Disease Progression; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D011859:Radiography; D012189:Retrospective Studies
references.citation: J Urol. 2004 Feb;171(2 Pt 1):615-20
references.pmid: 14713772
references.citation: Urology. 2000 Jul;56(1):67-70
references.pmid: 10869626
references.citation: J Urol. 2006 Feb;175(2):425-31
references.pmid: 16406965
references.citation: Urology. 2004 Nov;64(5):909-13
references.pmid: 15533476
references.citation: Urology. 2004 Sep;64(3):462-7
references.pmid: 15351571
references.citation: J Clin Oncol. 2003 Aug 15;21(16):3133-40
references.pmid: 12810695
references.citation: N Engl J Med. 1998 Apr 30;338(18):1272-8
references.pmid: 9562581
references.citation: Urology. 2002 Sep;60(3):421-7
references.pmid: 12350478
references.citation: AJR Am J Roentgenol. 2004 Mar;182(3):551-7
references.pmid: 14975944
references.citation: Urology. 2004 Jul;64(1):49-52
references.pmid: 15245934
references.citation: J Urol. 2001 Jul;166(1):6-18
references.pmid: 11435813
references.citation: J Urol. 2007 Mar;177(3):849-53; discussion 853-4
references.pmid: 17296355
references.citation: J Urol. 2005 Mar;173(3):713-5
references.pmid: 15711249
references.citation: Urol Oncol. 2004 Sep-Oct;22(5):410-4
references.pmid: 15464922
references.citation: Radiology. 1995 Dec;197(3):589-97
references.pmid: 7480724
references.citation: Can J Urol. 2004 Oct;11(5):2407-10
references.pmid: 15579229
references.citation: J Urol. 2007 Feb;177(2):466-70; discussion 470
references.pmid: 17222611
references.citation: Semin Urol Oncol. 1995 Nov;13(4):267-72
references.pmid: 8595550
references.citation: JAMA. 1999 May 5;281(17):1628-31
references.pmid: 10235157
references.citation: J Urol. 1999 Feb;161(2):408-11
references.pmid: 9915413
references.citation: J Natl Cancer Inst. 2006 Sep 20;98(18):1331-4
references.pmid: 16985252
references.citation: Cancer. 2004 Feb 15;100(4):738-45
references.pmid: 14770429