To evaluate the effect of prostate cancer zonal origin on the biochemical outcome after radical prostatectomy, to analyze clinicopathological features of tumors arising in different zones and to test the ability of the nomogram to predict the probability of transition zone cancer at radical prostatectomy.

Our cohort consisted of 1441 patients who underwent radical prostatectomy who did not receive neoadjuvant treatment. Clinicopathological characteristics and biochemical outcomes were compared between the groups of men with different zonal location of prostate cancer. Performance of the nomogram in predicting cancer location was evaluated with respect to discrimination and calibration.

The rates of positive margin were similar in men with transition zone and mixed tumors and were significantly higher than those with peripheral zone tumors. Most of the positive margins in patients with transition zone and mixed cancers were located at the apico-anterior part of the gland. On multivariate analysis, transition zone cancer location was associated with better biochemical recurrence-free survival (P = .043). The Harrel c-index of the models that did and did not include zonal origin of cancer was 0.810 and 0.807, respectively. Performance of the nomogram was poor.

The association between transition zone tumor origin and the risk of biochemical recurrence does not add important predictive value to the standard prognostic factors. Although information about the risk of prostate cancer involvement of the transition zone may be important for surgical planning, our ability to predict this risk preoperatively is limited.