To evaluate the tumor characteristics and prognostic factors in screen-detected prostate cancers in two successive screening rounds with a 4-year screening interval in the European Randomized Study of Screening for Prostate Cancer, section Rotterdam.

From 1993 to 2000, 42,376 men (21,210 in the screening arm and 21,166 in the control arm) were randomized and screened. Prostate-specific antigen testing, digital rectal examination, transrectal ultrasonography, and sextant biopsies were offered to the participants in the screening arm. A total of 1218 men with a biopsy indication at the first screening received an additional screening after 1 year (early recall). By 2004, all men had received their second screening. Interval carcinomas were defined as cancers detected during the screening interval and were identified by linkage with the Cancer Registry.

In the first round, 1014 prostate cancers were detected—24 in the men noncompliant to screening, 63 at the early recall screening, and 433 in the second round of screening. Also, 62 interval carcinomas were diagnosed. In the second screening round, the mean prostate-specific antigen value was lower (5.6 versus 11.1 ng/mL), advanced clinical stage T3–T4 was 7.1-fold less common, and 76.4% versus 61.5% of the biopsy Gleason scores were less than 7. In the first screening round, 13 regional and 9 distant metastases were detected; in the second round, 2 cases with distant metastasis were found.

Overall, a shift toward more favorable tumor characteristics was seen for the second round of screening. These results support the screening methods used and the interscreening interval of 4 years.