... measuring fPSA and calculating the percentage of fPSA aids in distinguishing cancer from other benign prostate conditions such as benign prostate hyperplasia, particularly for the population in the ... assays differ in calibration and response to different PSA forms We examined intermethod differences in total PSA (tPSA) and free PSA (fPSA) measurements We tested 157 samples with tPSA concentrations ... this subject http://www.labtestsonline.org.uk/ understanding/analytes /psa/ test.html Intermethod Differences in Results for Total PSA, Free PSA, and Percentage of Free PSA Patricia R Slev, PhD;...