PHI Test for Prostate Cancer

Controversy remains surrounding the use of the PSA test to screen for prostate cancer. This is due to the belief that the PSA test may lead to over-diagnosis and over-treatment in men with low-grade, less aggressive forms of the disease. Clinicians have been long awaiting a new approach to screen for prostate cancer because the current PSA test is simply not accurate enough. Prostate cancer diagnoses are on the rise, and the disease remains the second most common cancer in American men as well as the second leading cause of cancer deaths.

“My PSA is elevated, but I keep having negative biopsies. What does this mean?” This is a common question among many men under the care of a urologist. If you are familiar with prostate cancer, you know that having an elevated or rising PSA (prostate-specific antigen) may mean you have prostate cancer. While there are other possible reasons for an elevated or high PSA, prostate cancer instills the most fear. Therefore, having a high PSA, no sign of the other possible causes, and having had multiple negative biopsies causes much anxiety for patients because this means that the physician does not have a definite answer for their abnormal results. As for following-up, the patient usually has another biopsy in about six months, leaving the possibility for a future diagnosis of prostate cancer open. 


Did you know that the PSA test is not specific for prostate cancer? While the PSA test is used as a diagnostic and screening tool for prostate cancer, it is not specific for the disease. There are several other possibilities as to why your PSA may be elevated including an enlarged prostate, prostatitis, inflammation, or a urinary tract infection. But when the PSA is above 4.0 ng/ml, or is “abnormal”, and other possible causes have been ruled out, the next step for the patient is to have a prostate biopsy. If prostate biopsy is negative, but the PSA is still high, the patient usually has to have a repeat biopsy every six months or year. 

There are about 1.5 million prostate biopsies each year and about 25 million men have had at least one negative biopsy. Fortunately, there is a new blood test that has been developed to improve the diagnosis of prostate cancer. A new blood testdeveloped by Beckman Coulter Diagnostics called the Prostate Health Index (PHI) test is becoming widely available throughout the U.S. The PHI uses three different prostate specific markers, which makes the test three times more specific for prostate cancer compared to the current PSA test. The test gives doctors a more accurate picture in regards to what an elevated PSA level indicates as well as the probability of finding cancer on a prostate biopsy.

What is wrong with the current PSA test?  Simply, the PSA test is not specific to prostate cancer and as a result, many men often have unnecessary biopsies. PHI test is a simple, noninvasive blood test that is three times more specific than PSA in detecting prostate cancer, reducing unnecessary biopsies by 26 percent for men with PSA values from 2-10 ng/mL

How does it work? According to Innovative Diagnostic Laboratory, the PHI test measures total PSA as well as two special forms of the protein: free PSA (fPSA), and pro2PSA. tPSA includes all types of PSA circulating in the bloodstream, whether free or bound to other proteins; fPSA is PSA that circulates as a free protein, unattached to any other proteins; and pro2PSA is a form of PSA that is highly expressed in prostate cancer tissue and is associated with more aggressive disease. Using these three values, a PHI score is calculated. The PHI score provides a more accurate measurement to assess prostate cancer risk than any known PSA-based marker alone. And by using pro2PSA, the PHI test can detect more aggressive cancers. This reduces the harm many men experience with overtreatment.

The PHI test is now available nationwide through either Innovative Diagnostics Laboratory or Physicians Choice Laboratory Services. Where to get the PHI test: Prostate Health Index