Detection of microscopic extracapsular extension prior to radical prostatectomy for clinically localized prostate cancer



Objective To assess better techniques of clinical staging to identify the presence and location of extracapsular extension (ECE) and assist the surgeon in the selection of candidates for resection or preservation of neurovascular bundles during radical prostatectomy.

Patients and methods In a retrospective review of the records of 117 patients with clinically localized (31 T1 and 86 T2) prostate cancer treated with radical prostatectomy the results of digital rectal examination (DRE). real-time transrectal ultrasound (TRUS) and a retrospective review of static films were compared to assess their accuracy in the detection of ECE. The ultrasonic criterion for ECE was bulging or irregularity of the boundary echo adjacent to a hypoechoic lesion. On DRE, the criterion for ECE was palpable bulging of a nodule beyond the normal contour of the prostate. The reference standard was the presence and location of ECE in the whole-mount, serially sectioned radical prostatectomy specimens.

Results Microscopic ECE was present in 64 of the specimens (55%). There was no significant difference between DRE, prospective TRUS and retrospective TRUS in the overall accuracy of detection of ECE. However, when the results of DRE and TRUS were combined (if either was positive the result was considered positive), the positive predictive value (PPV) was 79% and the sensitivity (91%), with the overall accuracy increased significantly (P<0.05).

Conclusion The presence and precise location of microscopic ECE can be determined pre-operatively with reasonable accuracy using real-time ultrasound combined with the results of DRE.