Prostate cancer mortality in screen and clinically detected prostate cancer: estimating the screening benefit

To estimate the benefits of prostate-specific antigen (PSA) screening on prostate cancer (Pca) metastasis and Pca-specific mortality, we compared two populations with a well-defined difference in intensity of screening.

Between 1997 and 1999, a total of 11,970 men, aged 55-74 years, were included in the intervention arm of the European Randomised Study of Screening for Prostate Cancer (ERSPC) section Rotterdam. Control population consisted of 133,287 men, aged 55-74 years, between 1998 and 1999 in Northern Ireland (NI). Men were followed for Pca incidence, Pca metastasis and cause of death until 31st December 2006.

Median age in both groups was 63 years at study entry (p=0.184). In Rotterdam 94.2% of men and in NI 6% of men underwent PSA testing. In Rotterdam, 1153 men (9.6%) were diagnosed with Pca with median baseline PSA of 5.1 ng/ml. In NI, 3962 men (3.0%, p<0.001) were diagnosed with Pca with median baseline PSA of 18.0 ng/ml (p<0.001). The relative risk of Pca metastasis during observation in the intervention population compared to control population was 0.47 (95% confidence interval (CI), 0.35-0.63; p<0.001). The relative risk of Pca-specific mortality was also lower in the intervention population compared to the control population after a median follow-up of 8.5 years: 0.63 (95% CI, 0.45-0.88; p=0.008); absolute mortality reduction was 1.8 deaths per 1000 men.

A relative reduction in Pca metastasis of 53% and Pca mortality of 37% was observed in the intervention population after 8.5 years of observation. The impact of overdiagnosis, quality of life benefits and cost-effectiveness need to be assessed before population-based PSA screening can be recommended.