Purpose: The European Randomized Study of Screening for Prostate Cancer investigates the impact of screening on prostate cancer mortality and contributes to a better understanding of available screening tests. The present study evaluates the predictive value of a prostate specific antigen (PSA) increase to PSA 3.0 ng/ml or greater in a 4-year period in men who present with low PSA values (less than 3.0 ng/ml) at first screen.
Materials and methods: A total of 42,376 men were randomized to screening vs control in Rotterdam. Of 6,467 men 5,771 had PSA values of less than 3.0 ng/ml, did not undergo biopsy at baseline and were rescreened after 4 years with PSA 3.0 ng/ml or greater as biopsy indication. PSA progression in a 4-year interscreening interval is evaluated by determining the positive predictive values, detection rates and parameters of aggressiveness of round 2 cancers.
Results: PSA progression to more than 3.0 ng/ml occurred in 0.9%, 9.3% and 48.6% of men who presented with PSA values less than 1.0, 1 to 1.9 and 2 to 2.9 ng/ml, respectively, in round 1. Their respective positive predictive values amounted to 19.0%, 23.8% and 27.9%. Cancer detection rates increased with increasing PSA values in round 1. The distribution of low, moderate and high risk cancers depends on round 2 but not on round 1 PSA ranges.
Conclusions: PSA progression to the (arbitrary) cutoff value of 3.0 ng/ml and the diagnosis of prostate cancer in round 2 screening with a 4-year interval depends strongly on PSA values at the time of the 1st screen. These observations will be helpful to design future screening procedures. With levels less than 2.0 ng/ml PSA progression to levels of 3.0 ng/ml or greater is rare as it was seen only in 4.8% of all men.