Prostate cancer in Italy before and during the 'PSA era': survival trend and prognostic determinants.

The aim of the study was to investigate the variations in prostate cancer prognosis during a period of major diagnostic change, such as the introduction of the prostate-specific antigen (PSA) test. Data were provided by 14 Italian cancer registries (CRs). Incidence and follow-up information was collected for patients diagnosed from 1978 to 1994. Relative survival was computed taking into account incidence period, age, tumour stage and grade at diagnosis. A multivariate analysis was carried out to evaluate the independent simultaneous effect on survival of some prognostic determinants. A large geographical variability was observed: in 1993-1994 Italian survival rates ranged from 76% to 52%, with a north-south gradient. A striking prognostic improvement (up to +27 percentage points) between the late 1980s and the early 1990s occurred in almost all CRs, particularly with regard to younger patients. Multivariate analysis showed a strong influence of incidence period on survival, also after correction by tumour stage. The slowdown of metastatic cancers suggests that the survival improvement could be due both to the introduction of an effective opportunistic screening and to a quantitative change in the application of clinical treatment, even if the effect of the lead-time bias phenomenon has to be taken into account.