Impact of margin size on the incidence of local residual tumor after laparoscopic radical prostatectomy.

PURPOSE

Since October 2001 we have performed intraoperative frozen section (IFS) on the posterolateral areas of the radical prostatectomy specimen with bilateral nerve sparing. In cases of positive surgical margin (SMs) the corresponding neurovascular bundle (NVB) was resected. We evaluated the impact of several biological and pathological parameters on the incidence of local residual tumor in the NVB.

MATERIALS AND METHODS

A total of 487 laparoscopic radical prostatectomies with bilateral nerve sparing and IFS were performed between October 2001 and December 2003. When IFS was positive, the whole NVB was removed and analyzed after fixation in serial sections. The size of the positive SM was measured in its largest dimension. The association of NVB residual tumor with positive SM size, preoperative prostate specific antigen, pathological stage and Gleason score was analyzed using the t and chi-square tests, and logistic regression.

RESULTS

Of the 487 patients 84 had a positive SM on IFS. In 25 of the 84 additionally resected NVBs we found residual tumor. On univariate and multivariate analysis the only predictor of residual tumor was positive SM size (p<0.001). In all cases of a positive SM of 0.1 cm or less we found no residual tumor cells in the NVB.

CONCLUSIONS

In case of a positive SM in the posterolateral area of the prostatectomy specimen margin size is predictive of the incidence of residual tumor in the corresponding NVB. This finding could help management and the decision about local adjuvant treatment.