Preoperative and intraoperative risk factors for side-specific positive surgical margins in laparoscopic radical prostatectomy for prostate cancer.

OBJECTIVES

Identification of variables predicting positive surgical margins (PSMs) in patients undergoing laparoscopic radical prostatectomy (LRP) for clinically localized prostate cancer is lacking. Our objective was to determine preoperative risk factors and the association of ipsilateral degree of neurovascular bundle dissection (intraoperative factor) with side-specific PSMs in these patients.

MATERIAL AND METHODS

Between October 2002 and April 2005, one surgeon performed LRP on 407 previously untreated patients. Of 814 evaluable prostate sides, 728 harboured prostate cancer in the specimen and composed the study population. For each prostate side, we obtained clinical stage, biopsy Gleason, maximum percentage of tumour in the biopsy, suspected extracapsular extension (ECE) on endorectal coil magnetic resonance imaging (MRI), degree of neurovascular bundle (NVB) dissection, and PSMs. PSM was defined as cancer cells at the inked margins. Logistic regression analyses with random effects were generated.

RESULTS

Of the 728 prostate sides with cancer, 51 (7%) had at least one PSM. In multivariable analysis, higher PSA (p=0.01), Gleason score of 7 compared with < or =6 in the biopsy (p=0.04), lower prostate volume on MRI (p=0.01), and interfascial NVB dissection compared with intrafascial dissection (p=0.01) were associated with an increased risk of side-specific PSMs. Suspected ECE on MRI (p=0.9) and clinical stage (p=0.3) were not significantly associated with side-specific PSMs. A subset analysis of 321 patients with bilateral tumours did not show statistically significant differences in PSMs according to tumour side (p=0.3).

CONCLUSIONS

High serum prostate-specific antigen, biopsy Gleason score of 7, low prostate volume, and interfascial NVB dissection were independently associated with side-specific PSMs after LRP, and should be considered during planning of the LRP surgical strategy.