Objective: The aim of this work is to study variations of prostate cancer incidence by stage as a function of time and place in a region of France.
Material and methods: Retrospective observational survey conducted in five private and public urology centres representative of the various demographic features of the Nord-Pas-de-Calais region. In each centre, the medical records of the first 25 cases of prostate cancer diagnosed in 1998, 2002 and 2004, identified from histology laboratory data, were studied by means of a case report form evaluating the circumstances of diagnosis, PSA level, grade, stage (TNM 97, classification) and initial management.
Results: This analysis was based on 123, 124 and 125 patients in five centres in 1998, 2002 and 2004, respectively. The age at diagnosis ranged from 71.14 to 68.9 years between 1998 and 2004 (p=0.054). Median PSA decreased over this six-year period from 18 to 10.8 ng/ml. Between 1998 and 2004, the percentage of patients with localized cancer (PSA<20 ng/ml) increased from 44.8 to 66.4% (p<0.05), the percentage of patients with locally advanced cancer (PSA between 20 and 50 ng/ml) decreased from 17 to 9.6% (p<0.05), the percentage of patients with regional or distant metastatic disease (N1 and/or M1 and/or PSA>50 ng/ml) decreased from 29.4 to 22.4% (p<0.05) and the percentage of patients receiving curative treatment increased from 30 to 54.4% (p<0.005).
Conclusion: The prostate cancer incidence by stage varied between 1998 and 2004, with a significantly higher proportion of localized stages, which can be explained by the increased use of screening and diagnostic tests. Routine surveys can measure trends and the amplitude of incidence variations in the population of a region. A representative survey conducted in centres throughout France would allow evaluation of national trends between two publications of incidence by stage results in French registries.