title: The impact of frozen section analysis during partial nephrectomy on surgical margin status and tumor recurrence: a clinicopathologic study of 433 cases.
abstract: BACKGROUND
  Frozen section analysis (FSA) is frequently performed during partial nephrectomy (PN) to ensure complete tumor resection. We investigate the utility of intraoperative FSA by evaluating its impact on final surgical margin (SM) status and on patient outcomes.
  
  
  METHODS
  We retrospectively analyzed a consecutive series of patients (n = 433, including 326 with renal cell carcinomas [RCCs]) undergoing PN (n = 447; 136 open/311 laparoscopic) for a suspected renal tumor at the University of Rochester Medical Center from 2004 to 2012.
  
  
  RESULTS
  FSA was performed in 293 patients (67.7%) undergoing 300 PNs (67.1%). Overall, positive SMs were found significantly more often (P < .001) in the no FSA group (17.7%) than in the FSA group (4.3%). Performing FSA also resulted in significant decreases in the rate of positive SM in the following subgroups of patients with RCC undergoing PN laparoscopically: clear-cell (P = .002)/papillary (P = .041) subtypes, upper (P = .004)/mid (P = .022) pole tumors, exophytic (P = .029)/endophytic (P = .014) tumors, pT1a (P < .001)/pT1 (P < .001) tumors, and Fuhrman grades 1 to 2 (P = .004)/2 (P = .007) tumors. Kaplan-Meier analysis in RCC cases revealed that FSA did not considerably contribute to preventing recurrence (P = .114). However, performing FSA during laparoscopic PN strongly correlated with improved recurrence-free survival in patients with pT1 (P = .004) or exophytic (P = .011) RCC. No impact of FSA on recurrence was seen in any subgroup of patients undergoing open surgery.
  
  
  CONCLUSIONS
  Although FSA reduces the risk of positive SMs, our data may argue against routine FSA during PN that does not affect patient outcomes overall. However, FSA may be useful in select patients who have pT1 or exophytic tumor and undergo laparoscopic PN.
authors.affiliation: Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, Rochester, NY.
authors.forename: Sriram
authors.initials: S
authors.lastname: Venigalla
authors.forename: Guan
authors.initials: G
authors.lastname: Wu
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Miyamoto
mesh_terms: D002292:Carcinoma, Renal Cell / Q000601:surgery*; D018572:Disease-Free Survival; D005260:Female; D005629:Frozen Sections; D006801:Humans; D007680:Kidney Neoplasms / Q000601:surgery*; D010535:Laparoscopy; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000517:prevention & control* / Q000601:surgery; D009392:Nephrectomy; D012189:Retrospective Studies; D013534:Survival; D016896:Treatment Outcome
keywords: Intraoperative frozen section assessment; Partial nephrectomy; Renal cell carcinoma; Surgical margin; Tumor recurrence