Prostate Health Index (phi) blood test for Prostate Cancer
The phi – Prostate Health Index. This is a blood test now available that may help make the diagnosis of prostate cancer more accurately.
PSA and %freePSA are commonly used blood tests, which help identify men with prostate cancer. Although these tests can be useful in some men, the tests can be positive when no prostate cancer is present (or only a low risk prostate cancer is present), and the tests can be negative when an aggressive prostate cancer is present.
The phi, or Prostate Health Index test, is indicated in men with a PSA of 4-10. It uses an additional form of PSA (pro-PSA), and combines the reading with the PSA and %freePSA to produce a figure that may more accurately define a man’s risk of having an aggressive prostate cancer.
A recent study from large centres in the USA has demonstrated that:
- The phi can help to determine whether an elevated PSA is likely due to prostate cancer or benign changes.
- The ability of phi to correctly identify a man who does not have prostate cancer was greater than the PSA or %freePSA alone.
- The ability of phi to correctly identify a man with a significant prostate cancer was greater than the PSA or %freePSA alone.
- Using a phi value of 27 as a cut-off, 18% of men can avoid an unnecessary biopsy.
To read more details of this study, follow this link
It is important to realise that, while the phi test can improve the accuracy of blood tests for prostate cancer, it is not a perfect test, and is still subject to false-negatives and false-positives. It may be helpful for some, but not all men, and needs careful interpretation by a urologist, taking other findings into consideration.
The test is available in Australia, but there is no Medicare rebate, and it costs $95 (Aug 2013).
If you would like more information on the Prostate Health Index, please contact Nick Brook using the Web-form , or contact the Practice on 08 8267 1424.