title: Impact of tumor histology and grade on treatment success of percutaneous renal cryoablation.
abstract: BACKGROUND
  We analyzed oncological outcomes in patients who underwent percutaneous renal cryoablation (PRC) with documented renal cell carcinoma (RCC) by perioperative biopsy.
  
  
  METHODS
  Multicenter retrospective analysis of 153 patients [median follow-up 48 months] who underwent PRC from 09/2005 to 08/2014 was performed. We divided the cohort into patients who developed recurrence versus no recurrence. Kaplan-Meier analyses examined recurrence-free survival (RFS) according to grade and histology. Multivariable analysis (MVA) was performed to identify factors associated with tumor recurrence.
  
  
  RESULTS
  One hundred and fifty-three patients were analyzed [18 patients (11.8 %) with recurrence and 135 (88.2 %) patients without recurrence]. There were no differences between the groups with respect to demographics, RENAL score, and number of probes utilized. Recurrence group had larger tumor size (3.1 vs. 2.4 cm; p = 0.011), upper pole tumor location (p = 0.016), and greater proportions of high-grade tumor (33 vs. 0.7 %; p < 0.001) and clear cell histology (77.8 vs. 45.9 %; p = 0.011). Four-year RFS was 100 versus 80 % for grade 1 versus grade 2/3 tumors (p = 0.0002), and 97 versus 88 % for other RCC versus clear cell RCC (p = 0.07). MVA demonstrated tumor size >3 cm (OR 2.46; p = 0.019), clear cell histology (OR 2.12; p = 0.027), and high tumor grade (OR 2.33, p < 0.001) as independent risk factors associated with tumor recurrence.
  
  
  CONCLUSIONS
  Association of higher grade and clear cell histology with recurrence and progression suggests need for increased emphasis on preoperative risk stratification by biopsy, with grade 1 and non-clear cell RCC being associated with improved treatment success than higher grade and clear cell RCC.
authors.affiliation: Department of Urology, Moores UCSD Cancer Center, University of California San Diego School of Medicine, 3855 Health Sciences Drive, Mail Code: 0987, La Jolla, CA, 92093-0987, USA.
authors.forename: Alp Tuna
authors.initials: AT
authors.lastname: Beksac
authors.affiliation: Department of Radiology, University of California San Diego School of Medicine, La Jolla, CA, USA.
authors.forename: Gerant
authors.initials: G
authors.lastname: Rivera-Sanfeliz
authors.affiliation: Department of Urology, Moores UCSD Cancer Center, University of California San Diego School of Medicine, 3855 Health Sciences Drive, Mail Code: 0987, La Jolla, CA, 92093-0987, USA.
authors.forename: Catherine A
authors.initials: CA
authors.lastname: Dufour
authors.affiliation: Department of Urology, Moores UCSD Cancer Center, University of California San Diego School of Medicine, 3855 Health Sciences Drive, Mail Code: 0987, La Jolla, CA, 92093-0987, USA.
authors.forename: Unwanaobong
authors.initials: U
authors.lastname: Nseyo
authors.affiliation: Department of Urology, Moores UCSD Cancer Center, University of California San Diego School of Medicine, 3855 Health Sciences Drive, Mail Code: 0987, La Jolla, CA, 92093-0987, USA.
authors.forename: Zachary
authors.initials: Z
authors.lastname: Hamilton
authors.affiliation: Department of Urology, Moores UCSD Cancer Center, University of California San Diego School of Medicine, 3855 Health Sciences Drive, Mail Code: 0987, La Jolla, CA, 92093-0987, USA.
authors.forename: Sean W
authors.initials: SW
authors.lastname: Berquist
authors.affiliation: Department of Urology, Moores UCSD Cancer Center, University of California San Diego School of Medicine, 3855 Health Sciences Drive, Mail Code: 0987, La Jolla, CA, 92093-0987, USA.
authors.forename: Abd-elRahman
authors.initials: AE
authors.lastname: Hassan
authors.affiliation: Department of Urology, Moores UCSD Cancer Center, University of California San Diego School of Medicine, 3855 Health Sciences Drive, Mail Code: 0987, La Jolla, CA, 92093-0987, USA.
authors.forename: Omer A
authors.initials: OA
authors.lastname: Raheem
authors.affiliation: Department of Urology, Moores UCSD Cancer Center, University of California San Diego School of Medicine, 3855 Health Sciences Drive, Mail Code: 0987, La Jolla, CA, 92093-0987, USA.
authors.forename: Song
authors.initials: S
authors.lastname: Wang
authors.affiliation: Department of Urology, University of Tennessee Health Science Center, Memphis, TN, USA.
authors.forename: Robert W
authors.initials: RW
authors.lastname: Wake
authors.affiliation: Department of Radiology, University of Tennessee Health Science Center, Memphis, TN, USA.
authors.forename: Robert E
authors.initials: RE
authors.lastname: Gold
authors.affiliation: Department of Urology, Moores UCSD Cancer Center, University of California San Diego School of Medicine, 3855 Health Sciences Drive, Mail Code: 0987, La Jolla, CA, 92093-0987, USA. iderweesh@gmail.com.
authors.forename: Ithaar H
authors.initials: IH
authors.lastname: Derweesh
mesh_terms: D000368:Aged; D001706:Biopsy; D002292:Carcinoma, Renal Cell / Q000473:pathology / Q000601:surgery*; D003452:Cryosurgery / Q000379:methods*; D018450:Disease Progression; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D007680:Kidney Neoplasms / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology*; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome; D047368:Tumor Burden
keywords: Carcinoma, renal cell; Percutaneous renal biopsy; Percutaneous renal cryoablation; Recurrence; Tumor grade; Tumor histology