He pointed out that the 2006 Kattan preoperative nomogram has a concordance index of 0.79. Problematic to this is the potential mis-grading of the Gleason score used as a qualifying criterion. These investigators previously identified Insulin-like Growth Factor Binding Protein-3 (IGFBP3), Vascular Endothelium Growth Factor-D (VEGFD), Pigment Epithelium Derived Factor (PEDF) and Zinc-Alpha-2-Glycoprotein (ZAG) as preoperative serum biomarkers to distinguish between Gleason score 5 and 7.
Their goal was to determine if these biomarkers could help identify patients with biochemical recurrence following radical prostatectomy. A multiplex approach was developed to simultaneously measure IGFBP3, VEGFD, PEDF and ZAG in the preoperative serum of 57 patients from the Austrian Tyrol Prostate Cancer Screening Program. Thirty patients had a recurrence after surgery and 27 did not. The mean follow-up time was 8.25 years and mean time to progression was 2.7 years. The panel prediction performance was assessed using 500 times bootstrapping with logistic regression. Receiver operating characteristics curves and area under the curve (AUC) values were also generated as an indication of prediction accuracy. PSA alone predicted biochemical recurrence with AUC of 0.738. Combined with ZAG, a two-biomarker panel achieved an AUC of 0.751. Although the further inclusion of IGFBP3 improved the AUC to 0.758, the optimal sensitivity and specificity combination was observed with PSA and ZAG at 70% and 80%, respectively.
They concluded that validation studies are now necessary.
Presented by Sheng F. Oon, MD, et al. at the 26th Annual European Association of Urology (EAU) Congress - March 18 - 21, 2011 - Austria Centre Vienna, Vienna, Austria