Intraoperative frozen section analysis of urethral margin biopsies during radical prostatectomy

To evaluate the accuracy and potential clinical value of intraoperative frozen section analysis (FSA) on urethral margin (UM) tissue during radical prostatectomy. Positive surgical margins increase the risk of post-operative cancer recurrence. Positive surgical margins are frequently found at the apex. The utility of intraoperative FSA of the margins is controversial.

We reviewed a consecutive series of radical prostatectomy cases (n = 1669) performed at our institution, in which UMs were routinely evaluated by intraoperative FSA.

The submitted UM tissue contained cancer glands in 111 cases (6.7%). On FSA, the pathologists detected cancer in 55 cases (3.3%), missed cancer in 38 (2.3%), and reported atypical glands in 18 (1.1%). FSA of the UMs had a sensitivity of 59.1%, specificity of 99.8%, and positive and negative predictive value of 94.8% and 97.6%, respectively. The low sensitivity resulted from a substantial false-negative rate (n = 38), which was largely attributed to limited sampling on FSA (n = 31). Of the 55 patients (3.3%) whose positive UMs were detected by FSA, 20 (1.2%) had cancer-free margins after tissue re-excision. A positive final UM was associated with greater biochemical recurrence (P = .0073). However, the few patients limited the statistical analysis of the benefit of margin conversion through tissue re-excision (P = .35).

Although experienced pathologists can evaluate the UMs on FSA with good accuracy, FSA has a relatively low sensitivity. Our data have indicated a low yield and a questionable value of routine FSA during radical prostatectomy.