Does body mass index have an impact on the rate and location of positive surgical margins following robot assisted radical prostatectomy?

OBJECTIVE

Obesity has been shown to be associated with more aggressive prostate cancer. We sought to determine whether body mass index (BMI) has an impact on the rate and location of positive surgical margins (PSM) in robot-assisted laparoscopic radical prostatectomy (RLRP).

METHODS

Records of patients undergoing RLRP between the years 2003 and 2009 were retrospectively reviewed. We collected data regarding clinicopathologic data (i.e., age, BMI, PSA levels, Gleason score, pathologic stage, surgical margins status, and location). BMI was categorized as <25, 25-30, and >30 Kg/m(2). The rates of overall apical, peripheral, and prostate base (PB) PSM were compared across BMI groups.

RESULTS

Overall, 577 records were analyzed. Median age, PSA levels, and BMI were 60.1, 5.3, and 28.2, respectively. Percentage of Gleason score 4, 5, 6, 7, 8, 9 in the entire series was 0.2, 2.1, 40.7, 53, 2.3, and 1.7, respectively. Four hundred eighty-four (81.8%) cases were pathologically organ-confined. The overall incidence of PSM was 23.1% (n = 133) of those 10.2% apical, 3.6% PB and 14.2% peripheral. There were no statistically significant differences found in the rate of PSM by location between BMI groups; however, in the obese group there was a tendency toward slightly higher involvement of the PB with tumor in all stages and greater involvement of all anatomic areas in the T3 pathologic stage.

CONCLUSIONS

Although obesity has been associated with more aggressive prostate cancer, BMI does not appear to have statistically significant influence on the rate and location of PSM in RLRP. Larger studies are required to confirm these findings.