AUA 2018: Frozen Sections for Margins During Partial Nephrectomy Do Not Influence Recurrence Rates

San Francisco, CA USA ( Julien Dagenais, MD and colleagues made the argument that frozen sections for margins during partial nephrectomy do not influence recurrence rates. Even the era of robotic partial nephrectomy with the magnification and high definition vision, urologists are still anecdotally are still performing frozen sections at the tumor base. The reason to perform a frozen section is to confirm negative margin status for clinically localized renal cell carcinoma. However, their oncologic benefit remains unclear and there have been no studies investigating the long-term impact of frozen section on local or metastatic recurrence. The objective of this study was to determine whether the utilization of a frozen section for this purpose during partial nephrectomy influenced recurrence rates.

For this retrospective review, the authors identified 1,090 patients with (n=172) and without (n=918) frozen section during open and robotic partial nephrectomy between 2006 and 2016 for CLRCC at a high-volume tertiary care center. Standard follow-up protocols were employed, with imaging used to guide subsequent biopsy for confirmation. Frozen status and patient clinicodemographic and pathologic characteristics were correlated with recurrence using univariate and multivariate competing risk regression analyses with adjustment for all-cause mortality and baseline characteristics. Finally, administrative data was reviewed to calculate costs of frozen sections.

Over a median follow-up of 24.8 months, 4.1% patients had recurred. There was no difference in the cumulative incidence of recurrence between patients with and without frozen section (χ2=0.001, p=0.97). On multivariate competing risk analysis, frozen section was not associated with recurrence (HR 1.56, 95%CI 0.65-3.76), although this was not statistically significant. However, high tumor grade (3-4 vs.1-2: HR 2.45, 95%CI 1.16-5.14) and stage (>pT2 vs. pT1a: HR 2.86, 95%CI, 1.13-7.26) were associated with recurrence. The average direct charge per patient undergoing a frozen section was $902.

The strength of this study is the ability to have enough patients and events to perform adjusted multivariable analyses for performing appropriate analyses. A limitation of the study is the retrospective nature of the study. The author’s concluded that intraoperative for margins during partial nephrectomy did not predict decreased recurrence rates in a single-institution, high volume center. Finally, given the lack of associated benefit, and the added cost, the utilization of frozen section during partial should be limited.

Presented by: Julien Dagenais, Cleveland Clinic Foundation, Cleveland, OH

Co-Authors: Juan Garisto, Jaya Chavali, Jihad Kaouk, Cleveland, OH

Written by: Zachary Klaassen, MD, Urologic Oncology Fellow, University of Toronto, Princess Margaret Cancer Centre, Twitter: @zklaassen_md, at the 2018 AUA Annual Meeting - May 18 - 21, 2018 – San Francisco, CA USA