Nomogram use for the prediction of indolent prostate cancer: Impact on screen-detected populations

BACKGROUND. Screening for prostate cancer has resulted in an increased incidence-to-mortality ratio. Not all cancers deserve immediate treatment. It has therefore become more important to be able to identify those cases of screen-detected prostate cancer most likely to show indolent behavior. METHODS. The Kattan-nomogram for the prediction of indolent prostate cancer was validated and recalibrated for use in a screening setting. The recalibrated nomogram was used to calculate the number of men who were predicted to have indolent cancer in a screen-detected cohort from the European Randomized study of Screening for Prostate Cancer (ERSPC), section Rotterdam. RESULTS. Of 1629 cancers detected in 2 subsequent screening rounds 825 were suitable for nomogram use. The remainder were very unlikely to have indolent cancer. A total of 485 men (485 of 825 = 59%) were predicted to have indolent cancer, which is 30% (485 of 1629) of all screen-detected cases. Cancers found at repeated screening after 4 years had a higher probability of indolent cancer than cases from the prevalence screening (44% vs 23%; P < .001). CONCLUSIONS. The current nomogram can identify substantial groups of screen-detected cancers that are likely indolent and can therefore be considered for active surveillance.