Impact of ethnicity on surgical margins at radical prostatectomy

Abstract

To determine if the rate of positive surgical margins (PSMs), and in particular apical PSMs, at radical prostatectomy (RP) for prostate cancer, is higher in African-American (AA) than Caucasian men, given their often narrower and deeper pelvis. From 1999 to 2007, 3145 consecutive patients underwent RP, either open retropubic (RRP) or laparoscopic (LRP), with no previous treatment, by one of five surgeons. Multivariate logistic regression was used to determine the effect of ethnicity (AA vs Caucasian) on overall and site-specific PSMs, adjusting for age, body mass index, RP approach (RRP vs LRP), surgeon, surgeon case number, year of surgery, preoperative serum prostate-specific antigen level, specimen weight, estimated blood loss, pathological organ-confined status, and pathological Gleason score. In all, 205 men were AA and 2940 Caucasian; PSMs were identified in 376 (12.0%) men, 35 (17.1%) in AA and 341 (11.6%) in Caucasian men. PSMs were identified at the apex in 148 (4.7%), the bladder neck in 29 (0.9%), posteriorly in 169 (5.4%), and anteriorly in 78 (2.5%) men. For apical PSM, ethnicity was a significant predictor, with an odds ratio of 1.76 (95% confidence interval 1.01-3.04, P = 0.045) for AA vs Caucasian, independent of pathological organ-confined status and PSA level. Ethnicity was not a significant independent predictor of overall PSMs or PSMs at other sites (bladder neck, posteriorly, or anteriorly). The rate of apical PSMs, but not overall PSMs, at RP was higher in AA than Caucasian men, controlling for other covariates. Further investigation is necessary to determine if pelvic shape is responsible for this observation.