Comparison of prostate cancer survival in Germany and the United States: Can differences be attributed to differences in stage distributions?
A partir de données de 13 registres américains et 12 registres allemands des cancers, cette étude évalue l'impact de l'utilisation du test du dosage du PSA sur l'incidence du cancer de la prostate, le stade au diagnostic, la survie relative et la mortalité, en comparant les données de ces deux pays sur la période 1999-2010
Objectives : To better understand influence of prostate-specific antigen (PSA) screening and other health system determinants on prognosis of prostate cancer (PCa), up-to-date relative survival (RS), stage distributions, and trends in survival and incidence in Germany were evaluated and compared with the United States (US). Patients and Methods : Incidence and mortality rates for Germany and the US for the period 1999 to 2010 were obtained from the Center for Cancer Registry Data at the Robert Koch Institute and the US Surveillance Epidemiology and End Results (SEER) database. For analyses on stage and survival, data from 12 population-based cancer registries in Germany and from the SEER-13 database were analyzed. Patients (≥15 years) diagnosed with PCa (1997-2010), with mortality follow-up to December 2010 were included. 5- and 10-year RS and survival trends (2002-2010) were calculated using standard and model-based period analysis. Results : Between 1999 and 2010, PCa incidence decreased in the US but increased in Germany. Nevertheless incidence remained higher in the US throughout the study period (99.8 vs. 76.0 per 100,000 in 2010). The proportion of localized disease significantly increased from 51.9% (1998-2000) to 69.6% (2007-2010) in Germany and from 80.5% (1998-2000) to 82.6% (2007-2010) in the US. Mortality slightly decreased in both countries (1999-2010). Overall, 5- and 10-year RS was lower in Germany (93.3%; 90.7%) than in the US (99.4%; 99.6%) but comparable after adjustment for stage. The same patterns were observed in age-specific analyses. Improvements observed in PCa survival between 2002-2004 and 2008-2010 (5-year RS: 87.4; 91.2; +3.8% units) disappeared after adjustment for stage (p=0.8). Conclusion : The survival increase in Germany and the survival advantage in the US might be explained by differences in incidence and stage distributions over time and across countries. Effects of early detection or a lead time bias due to the more widespread utilization and earlier introduction of PSA testing in the US are likely to explain the observed patterns.