Preoperative predictors of cancerous involvement of the neurovascular bundles in patients with localized prostate cancer

BACKGROUND: The purpose of this study was to identify preoperative variables that would be useful in objectively selecting prostate cancer patients for nerve-sparing prostatectomy. METHODS: Twenty-six patients with clinical T1c-T2c cancers were evaluated for cancerous involvement in the region of the neurovascular bundles (NVB) from prostatectomy specimens. Preoperative prostate-specific antigen (PSA) and pathologic features in systematic biopsy specimens also were reviewed. RESULTS: A total of eight (31%) patients had cancerous involvement in the region of the NVB, including four on the right side, three on the left side and one on both sides. The percentage of each biopsy specimen occupied by the cancer was scored from zero to four and defined as the positive biopsy score. Preoperative PSA (P = 0.046), mean positive biopsy score (total sum of positive biopsy score divided by number of biopsy specimens; P = 0.001), number of cores containing cancer (P = 0.011), percentage of cores involved (P = 0.036) and maximum positive biopsy score (P < 0.001) were significant for predicting cancerous involvement in the NVB region using univariate analysis. However, only the mean positive biopsy score was independently significant according to multivariate analysis. To predict cancerous involvement in the region of each NVB, we found that ipsilateral mean positive biopsy score (total sum of corresponding positive biopsy score divided by number of ipsilateral biopsy specimens), number of cores involved on the ipsilateral side, percentage of cores involved on the ipsilateral side and maximum positive biopsy score on the ipsilateral side were significant predictive variables: the ipsilateral mean positive biopsy score being most appropriate for clinical practice. CONCLUSION: Ipsilateral mean positive biopsy score in systematic biopsy specimens can be an appropriate variable for selecting patients with localized prostate cancer for nerve-sparing prostatectomy.