The impact of frozen section analysis during partial nephrectomy on surgical margin status and tumor recurrence: A clinicopathologic study of 433 cases

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. Patients and 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.