Figure 4

Validation of candidate biomarkers for the diagnosis of PCa. (A) 2-DE profiles of TF, AMBP and HP abundance in independent urine samples from BPH and PCa patients obtained by 2-D DIGE. Proteins with differential abundance were represented by clusters of 3–4 spots, highlighted with oval lines. Four gels corresponding to samples from each group were shown. (B) TF, AMBP and HP levels in urine of PCa and BPH patients, expressed as relative ratio to urine creatinine and obtained by immunoturbidimetry. AMBP level in PCa was significantly higher than that in BPH while TF and HP levels in PCa were significantly lower than in BPH (Mann–Whitney U-test, P < 0.05). In the combined dot/box plot graphs, concentration data (blue diamond), median (−), 25th and 75th percentiles and mean (+) are shown. (C) Urinary TF, AMBP and HP distinguish PCa on independent series of urine samples from patients with PCa and BPH. The optimal cutoffs for the proteins were: 12.81 mg TF/g creatinine (93.8% specificity, 56.3% sensitivity); 6.51 mg AMBP/g creatinine (50.0% specificity, 93.8% sensitivity); 2.40 mg HP/g creatinine (56.3% specificity, 93.8% sensitivity). ROC curves were based on series of 32 urine samples. (D) The diagnostic accuracy of TF, AMBP and HP combinations using logistic regression model. The combination AMBP and HP yielded highest diagnostic accuracy (AUC = 0.848).