Postoperative prostate-specific antigen nadir improves accuracy for predicting biochemical recurrence after radical prostatectomy: Results from the Shared Equal Access Regional Cancer Hospital (SEARCH) and Duke Prostate Center databases.

OBJECTIVES: We previously showed that prostate-specific antigen (PSA) nadir after radical prostatectomy (RP) significantly predicts biochemical recurrence (BCR). Herein, we sought to explore the effect of including PSA nadir into commonly used models on their accuracy to predict BCR after RP. METHODS: This was a retrospective analysis of 943 and 1792 subjects from the Shared Equal Access Regional Cancer Hospital (SEARCH) and Duke Prostate Cancer (DPC) databases, respectively. The discrimination accuracy for BCR of seven previously published models was assessed using concordance index and compared with and without adding PSA nadir level in SEARCH. Using data from SEARCH, we developed a new nomogram incorporating PSA nadir to other known predictors (preoperative PSA, pathological Gleason score, PSA nadir level, surgical findings, prostate weight, body mass index and race) of BCR and externally validated it in the DPC. RESULTS: In SEARCH, the mean concordance index across all seven nomograms was 0.687. After the inclusion of PSA nadir, the concordance index increased by nearly 7% (mean=0.753). The concordance index of the new nomogram in SEARCH was 0.779 (bias-corrected=0.767), which was 5% better than the next best model. In DPC, the new nomogram yielded a concordance index of 0.778. CONCLUSION: The addition of postoperative PSA nadir to commonly used nomograms increased their accuracies by nearly 7%. Based upon this, we developed and externally validated a new nomogram, which was well calibrated and highly accurate, and is a potentially valuable tool for patients and physicians to predict BCR after RP.

A single-institution comparison between radical perineal and radical retropubic prostatectomy on perioperative and pathological outcomes for obese men: an analysis of the Duke Prostate Center database.

OBJECTIVES: To examine the association between body mass index (BMI) and operative time, estimated blood loss (EBL), and adverse pathologic features in patients undergoing either radical perineal prostatectomy (RPP) or radical retropubic prostatectomy (RRP). METHODS: We performed a retrospective analysis of 1006 patients treated with RPP or RRP at our institution from 1988 to 2005. Operative times and EBL were compared among BMI groups for both RPP and RRP. The odds ratio of positive surgical margins was estimated for the BMI categories using logistic regression after adjusting for preoperative and pathologic characteristics. RESULTS: Increased BMI was significantly associated with increased operative time and EBL for men treated with either RPP or RRP (all P < or = 0.03), though the associations were weak (all Spearman r < or = 0.19). After adjusting for multiple clinical preoperative characteristics, higher BMI was associated with positive surgical margins among all patients (P trend <0.001). The association between obesity and surgical margins remained after adjusting for pathologic characteristics (P trend = 0.001) with similar patterns among RRP (P trend = 0.03) and RPP (P trend = 0.01) patients. CONCLUSIONS: For mildly obese men, both RPP and RRP are associated with a similarly increased risk of higher EBL, longer operative time, and positive surgical margins. These data do not provide evidence to suggest that RPP should be preferred over RRP for mildly obese men. Further study is needed among men with a very high BMI.