Site-specific positive margins at radical prostatectomy: Assessing cancer-control benefits of wide excision of the neurovascular bundle on a side with cancer on biopsy

OBJECTIVE: To determine the potential risk of biopsy-selected nerve-sparing surgery based on the findings of site-specific extracapsular extension (ECE) and positive surgical margins (PSMs) in the area of the neurovascular bundle in radical prostatectomy specimens. PATIENTS AND METHODS: Controlling for surgical technique and pathological interpretation, 221 consecutive patients had their neurovascular bundles removed on the side with a positive biopsy. The surgical specimens were reviewed for ECE and PSM status, specifically in the area of the neurovascular bundle, from apex to base. RESULTS: Of the 221 patients, 38% had ECE and 43 (20%) had a PSM in the area of the neurovascular bundle. This equates to a ratio of 51% for PSM/ECE. An additional 42 men (18%) had ECE with negative margins, but would have been at potential risk for PSMs if the neurovascular bundle had been preserved. CONCLUSION: Preserving the neurovascular bundle on the side with a positive biopsy could result in a significantly greater incidence of PSM than with wide excision. Optimizing cancer control may require excision of the neurovascular bundle on a side known to have cancer on biopsy. In future site-specific analyses, the PSM/ECE ratio could be used as a marker comparing cancer-control outcomes from studies with differing technical approaches and indications for nerve-sparing surgery.