Table 2. Univariate and multivariate analysis predicting the probability of pT3 by pathologic stage.
| Predictor | Univariate analysis | Multivariate analysis | |||
|---|---|---|---|---|---|
| AUC of individual predictor variables | OR; p-value | Base model OR; p-value | Base model with %p2PSA; p-value | Base model with PHI; p-value | |
| Age | 0.428 | 0.977; 0.289 | |||
| Prostate volume | 0.496 | 1.016; 0.093 | |||
| Clinical stage | 0.653 | 5.626; <0.001 | 2.726; 0.273 | 2.734; 0.381 | 2.196; 0.451 |
| Percentage of positive biopsy core | 0.598 | 2.105; <0.001 | 1.953; 0.083 | 1.879; 0.096 | 1.882; 0.085 |
| Biopsy Gleason sum | 0.753 | 9.492; <0.001 | 4.493; 0.002 | 1.952; 0.059 | 1.812; 0.061 |
| PSA density | 0.573 | 2.291; <0.001 | 1.156; 0.072 | 1.120; 0.125 | 1.156; 0.149 |
| tPSA | 0.720 | 1.162; <0.001 | 1.157; 0.062 | 1.182; 0.045 | 1.142; 0.053 |
| fPSA | 0.603 | 1.135; 0.293 | |||
| %fPSA | 0.321 | 0.001; <0.001 | 0.089; 0.568 | 0.758; 0.883 | 0.074; 0.766 |
| p2PSA | 0.774 | 1.068; <0.001 | |||
| %p2PSA | 0.850 | 10.948; <0.001 | 13.145; <0.001 | ||
| PHI | 0.913 | 1.197; <0.001 | 1.213; <0.001 | ||
| AUC of multivariate models | 0.849 | 0.939 | 0.951 | ||
| Gain in predictive accuracy (%, p-value) | 9.0 (<0.001) | 10.2 (<0.001) | |||
AUC, area under the curve; OR, odds ratio; PHI, prostate health index; PSA, prostate-specific antigen; tPSA, total PSA; fPSA, free PSA; %fPSA, the percentage of free PSA to total PSA; %p2PSA, the percentage of p2PSA to free PSA.
The AUC reflects the predictive values of individual variables (columns) and of the multivariate models in predicting the probability of pT3.