Prostatic Health Index (phi)

by | Sep 4, 2013 | Blog, PSA testing


There are different aspect to PSA (prostatic Specific Antigen) which can be evaluated to improve the utility of the test. Traditionally this has included comparison to the age specific value, median, velocity and free/total ratio.  Recently,a new addition has become available in Australia which reported to be more specific for prostate cancer than other aspects to the PSA. It is called the truncated proPSA (p2PSA). p2PSA is part of the free PSA component, and is found in higher amounts in individuals with prostate cancer than in those with benign conditions affecting the prostate. The combination of proPSA, free PSA and total PSA  calculated together produces a result called the Prostatic Health Index (phi). This  result appears to produce a significant  improvement in the specificity for detecting prostate cancer over and above what can be achieved with a standard PSA test alone. A greater specificity means that we are less likely to have false positive test results and therefore hopefully less unnecessary biopsies being performed.

The Prostatic Health Index (phi) appears to be of most benefit for individuals with a total PSA value between 2-10.  The phi is reported as a risk, being low 0-22.9, intermediate 23-44.9 and high >45.

Currently, the Prostate Health Index (phi) is available at different labs for an additional fee of around $90. Talk to your urologist about the utility of adding in this test for your particular situation.