Stage migration in localized prostate cancer has no effect on the post-radical prostatectomy Kattan nomogram

To investigate the effect of prostate-specific antigen (PSA) testing on stage migration in an Australian population, and its consequences on the prognostic accuracy of the post-radical prostatectomy (RP) Kattan nomogram, as in North America widespread PSA testing has resulted in prostate cancer stage migration, questioning the utility of prognostic nomograms in this setting.

The study comprised 1008 men who had consecutive RP for localized prostate cancer between 1991 and 2001 at one institution. Two groups were assessed, i.e. those treated in 1991-96 (group 1, the early PSA era), and 1997-2001 (group 2, the contemporary PSA era). Differences in clinicopathological features between the groups were analysed by chi-squared testing and survival modelling. Individual patient data were entered into the post-RP Kattan nomogram and the efficacy assessed by receiver- operating characteristic curve analysis.

Patients in group 2 had lower pathological stage disease (P = 0.01) and fewer cancers with Gleason score > or =8 (P < 0.001) than group 1. Multivariate analysis identified preoperative serum PSA level (P < 0.01) and Gleason score (P < 0.01) as strong predictors of biochemical relapse in both groups. In group 2 pathological stage was not significant, but margin involvement became highly significant (P = 0.004). There was no difference in the predictive accuracy of the Kattan nomogram between the groups (P = 0.253).

These findings show a downward stage migration towards organ-confined disease after the introduction of widespread PSA testing in an Australian cohort. Despite this, the Kattan nomogram remains a robust prognostic tool in clinical practice.