A risk-based strategy improves prostate-specific antigen-driven detection of prostate cancer.

BACKGROUND: Screening for prostate cancer (PC) is controversial due to uncertainties about its efficiency.

OBJECTIVE: We aimed to develop strategies to reduce the number of unnecessary biopsies while still detecting most clinically important PC cases.

DESIGN, SETTING, AND PARTICIPANTS: In 1850 men initially screened and biopsied (prostate-specific antigen [PSA] value > or =3.0 ng/ml) in the Rotterdam section of the European Randomized Study of Screening for Prostate Cancer, we calculated both the probability of having a positive lateralized sextant biopsy [P(biop+)] and the probability of having an indolent cancer [P(ind)] if PC was detected at biopsy (n=541). Analyses of repeat screening included 225 cancers in 1201 men.

INTERVENTIONS: The P(biop+) was based on applying a logistic regression model that included ultrasound volume, digital rectal exam, and transrectal ultrasound in addition to the PSA value. The P(ind) was based on a recently validated nomogram. MEASUREMENTS AND LIMITATIONS: At initial screening the fraction of positive biopsies was 29% (541 of 1850). Applying an additional P(biop+) cut-off of 12.5% implied that 613 of the 1850 men (33%) would not have been biopsied. This would result in an increase in the positive predictive value (PPV) to 38% (468 of 1237). At repeat screening a similar P(biop+) cut-off would result in an increase in the PPV from 19% (225 of 1201) to 25% (188 of 760). Thirteen percent of PC cases would not have been diagnosed, of which 70% (initial screening) and 81% (repeat screening) could be considered as potentially indolent. None of the deadly PC cases would have been missed. A PSA cut-off of > or =4.0 ng/ml resulted in similar numbers of biopsied cases saved but considerably higher numbers of missed diagnoses.

CONCLUSIONS: An individualized screening algorithm using other available prebiopsy information in addition to PSA level can result in a considerable reduction of unnecessary biopsies. Very few important PC cases, for which diagnosis at a subsequent screening visit might be too late for treatment with curative intent, would be missed.