Changing role of 3 screening modalities in the European randomized study of screening for prostate cancer (Rotterdam)

Abstract

A randomized screening trial was started in Europe to show the effect of early detection and treatment of prostate cancer on mortality (European Study on Screening of Prostate Cancer). In one centre (Rotterdam), the screening protocol initially consisted of 3 screening tests for all men: prostate-specific antigen (PSA), digital rectal examination (DRE) and transrectal ultrasonography (TRUS). A PSA value of ≥4 ng/ml and/or an abnormality on DRE and/or TRUS were taken to indicate that biopsy was required. In this study, we examined the possibilities for a more efficient screening protocol. A logistic-regression model was used to predict the number of cancers for PSA < 4 ng/ml if all men were biopsied (predictive index, PI). Effects of a change in PSA cut-off on the screening results were explored. Weights were applied to procedures and cancers to explore the possibility of expressing differences between protocols in one overall figure. Biopsies in men with PSA < 1 ng/ml and a positive DRE or TRUS were very inefficient. Applying DRE and TRUS only in the PSA ranges 1.5 to 3.9 and 2 to 3.9 ng/ml to determine whether a biopsy was required would result in a decrease of 29 to 36% in biopsies and a decrease of 5 to 8% in cancers. However, the results of DRE and TRUS could not be duplicated entirely. A protocol with only PSA ≥ 3 ng/ml as a direct biopsy indicator resulted in a decrease of detected cancers by 7.6% and of biopsies by 12%, also a much simpler screening procedure. Use of the PI would give more efficient protocols, but this should be viewed as a preliminary finding, with the disadvantage of necessitating many additional screening visits. Since the results of DRE and TRUS could not be duplicated, a change in protocol towards PSA ≥ 3 ng/ml appears acceptable. If this proves effective, a final judgement about the optimal combination of screening tests may be made. Int. J. Cancer (Pred. Oncol.) 84:437–441, 1999. © 1999 Wiley-Liss, Inc.