Validity of PSA, free/total PSA ratio and complexed/total PSA ratio measurements in men with acute urinary retention.

The reliability of serum prostate specific antigen (PSA) measurements in men with acute urinary retention is unclear. Total PSA, free and complexed PSA were measured, and the free/total (f/t) PSA and complexed/total (c/t) PSA ratios calculated, prior to catheterisation and at 48 and 72 h post-catheterisation in 39 men with acute retention. Subsequent histology showed 12 patients had prostate cancer and 27 benign prostatic hypertrophy. Serum free and total PSA fell following catheterisation, while complexed PSA rose during the first 48 h then subsequently fell. The f/t PSA and c/t PSA ratios provided the best discrimination at 48–72 h with 100% sensitivity and 75–82% specificity.Prostate Cancer and Prostatic Diseases (2001) 4, 167–172. [ABSTRACT FROM AUTHOR]