title: Comparison of partial nephrectomy and percutaneous ablation for cT1 renal masses.
abstract: BACKGROUND
  Partial nephrectomy (PN) is a preferred treatment for cT1 renal masses, whereas thermal ablation represents an alternative nephron-sparing option, albeit with higher reported rates of recurrence.
  
  
  OBJECTIVE
  To review our experience with PN, percutaneous radiofrequency ablation (RFA), and percutaneous cryoablation for cT1 renal masses.
  
  
  METHODS
  A total of 1803 patients with primary cT1N0M0 renal masses treated between 2000 and 2011 were identified from the prospectively maintained Mayo Clinic Renal Tumor Registry.
  
  
  METHODS
  PN compared with percutaneous ablation.
  
  
  METHODS
  Local recurrence-free, metastases-free, and overall survival rates were estimated using the Kaplan-Meier method and compared with log-rank tests.
  
  
  CONCLUSIONS
  Of the 1424 cT1a patients, 1057 underwent PN, 180 underwent RFA, and 187 underwent cryoablation. In this cohort, local recurrence-free survival was similar among the three treatments (p=0.49), whereas metastases-free survival was significantly better after PN (p=0.005) and cryoablation (p=0.021) when compared with RFA. Of the 379 cT1b patients, 326 patients underwent PN, and 53 patients were managed with cryoablation (8 RFA patients were excluded). In this cohort, local recurrence-free survival (p=0.81) and metastases-free survival (p=0.45) were similar between PN and cryoablation. In both the cT1a and cT1b groups, PN patients were significantly younger, with lower Charlson scores and had superior overall survival (p<0.001 for all). Limitations include retrospective review and selection bias.
  
  
  CONCLUSIONS
  In a large cohort of sporadic cT1 renal masses, we observed that recurrence-free survival was similar for PN and percutaneous ablation patients. Metastases-free survival was superior for PN and cryoablation patients when compared with RFA for cT1a patients. Overall survival was superior after PN, likely because of selection bias. If these results were validated, an update to clinical guidelines would be warranted.
  
  
  RESULTS
  Partial nephrectomy and percutaneous ablation for small (<7-cm) and localized renal masses are associated with similar rates of local recurrence.
authors.affiliation: Department of Urology, Mayo Clinic and Mayo Medical School, Rochester, MN, USA. Electronic address: Thompson.robert@mayo.edu.
authors.forename: R Houston
authors.initials: RH
authors.lastname: Thompson
authors.affiliation: Department of Radiology, Mayo Clinic and Mayo Medical School, Rochester, MN, USA.
authors.forename: Tom
authors.initials: T
authors.lastname: Atwell
authors.affiliation: Department of Radiology, Mayo Clinic and Mayo Medical School, Rochester, MN, USA.
authors.forename: Grant
authors.initials: G
authors.lastname: Schmit
authors.affiliation: Department of Health Sciences Research, Mayo Clinic and Mayo Medical School, Rochester, MN, USA.
authors.forename: Christine M
authors.initials: CM
authors.lastname: Lohse
authors.affiliation: Department of Radiology, Mayo Clinic and Mayo Medical School, Rochester, MN, USA.
authors.forename: A Nicholas
authors.initials: AN
authors.lastname: Kurup
authors.affiliation: Department of Radiology, Mayo Clinic and Mayo Medical School, Rochester, MN, USA.
authors.forename: Adam
authors.initials: A
authors.lastname: Weisbrod
authors.affiliation: Department of Urology, Mayo Clinic and Mayo Medical School, Rochester, MN, USA.
authors.forename: Sarah P
authors.initials: SP
authors.lastname: Psutka
authors.affiliation: Department of Urology, Mayo Clinic and Mayo Medical School, Rochester, MN, USA.
authors.forename: Suzanne B
authors.initials: SB
authors.lastname: Stewart
authors.affiliation: Department of Radiology, Mayo Clinic and Mayo Medical School, Rochester, MN, USA.
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Callstrom
authors.affiliation: Department of Pathology, Mayo Clinic and Mayo Medical School, Rochester, MN, USA.
authors.forename: John C
authors.initials: JC
authors.lastname: Cheville
authors.affiliation: Department of Urology, Mayo Clinic and Mayo Medical School, Rochester, MN, USA.
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Boorjian
authors.affiliation: Department of Urology, Mayo Clinic and Mayo Medical School, Rochester, MN, USA.
authors.forename: Bradley C
authors.initials: BC
authors.lastname: Leibovich
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002292:Carcinoma, Renal Cell / Q000401:mortality / Q000556:secondary / Q000601:surgery*; D017115:Catheter Ablation / Q000009:adverse effects / Q000401:mortality; D003452:Cryosurgery / Q000009:adverse effects / Q000401:mortality; D018450:Disease Progression; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D007680:Kidney Neoplasms / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D008910:Minnesota; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D009392:Nephrectomy / Q000009:adverse effects / Q000379:methods* / Q000401:mortality; D016016:Proportional Hazards Models; D012042:Registries; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome; D047368:Tumor Burden
keywords: Ablation techniques; Cryosurgery; Kidney neoplasms; Partial nephrectomy