BACKGROUND. Prostate cancer screening is studied in a randomized trial in Antwerp, Belgium. The case group receives three screening tests (DRE, TRUS, and PSA). Intermediate evaluation shows that only 1/3 of the biopsy results is positive (35/125). The proposed analysis identifies variables that determine the biopsy outcome. METHODS. Multiple logistic regression analysis is used to regress biopsy results (n = 125) by age (60-74), PSA, PSA-D, prostate volume, TRUS, and DRE. Continuous variables are transformed into quartile values. Robustness of the outcome is tested with ROC and sensitivity analysis on age. RESULTS. Biopsy outcomes are best explained (82.3%) by PSA, DRE, and DRE related to volume. Volume is more sensitive than age to explain the biopsy result. PSA-D, instead of PSA, does not procure more precise information when a high PSA cut-off level is used.
Restricting the analysis to the 60-70-year-old age group shows that volume is more sensitive. ROC-analysis confirms the findings. CONCLUSIONS. When performing prostate cancer multitest screening among a wide age range, the use of uniform screening criteria is difficult to accept due to differences in prostate volume. Logistic regression analysis is an appropriate method to identify cut-off levels for prostate volume.