what is the most appropriate test in detecting prostate cancer in patients with intermediate prostate specific antigen levels?

abstract   background: regarding the variety of tests present for detecting and also screening prostate cancer and also bearing in mind the advantages and disadvantages of these tests we decided to re-evaluate these tests (total prostate specific antigen and all of its modifications) in detecting prostate cancer in men with intermediate serum psalevels.   methods: following a cross sectional study, 100 consecutive men with intermediate serum psa levels and normal digital rectal examination (dre) were incorporated. total and free psa levels and trus-guided systematic prostate biopsy were performed. psa density, percent free psa and percent free psa density were calculated and compared. statistical analysis was carried out using stata8 se.   results: overall, 27 patients had prostate cancer and 73 had benign prostate pathology. psa density had the greatest area under the curve (auc) which was significantly higher than percent free psa density (0.685 vs. 0.448, p< 0.001). the auc of percent free psa density was not different between benign and malignant biopsy results nor was significantly higher than the auc of percent free psa (0.308) or any other screening tests.   conclusion: psadensity was the most accurate screening test for prostate cancer in patients with psa levels of 4-10 ng/ml and normal dre. the percent free psa density was not significantly more accurate than percent free psa and regarding the costs of transrectal ultrasonography, it can be concluded that the percent free psa is more cost-effective and hence more appropriate than percent free psa density to screen prostate cancer.