PHI – Prostate Health Index for Detection and Screening for Prostate Cancer
Dr. Alex Shteynshlyuger is a fellowship-trained urologic oncologist and a robotically-trained surgeon who specializes in all aspects of care for early, advanced and metastatic prostate cancer. He is a member of the Society for Urologic Oncology as well as American Society for Clinical Oncology.
PHI Test: When New Is Better
PHI or Prostate Health Index is a new test that improves on the PSA test. PHI is actually an improved variation of the PSA test.
Essentially PHI uses a formula that combines a new test, pro-PSA (also called p2PSA), with two established (currently used) tests: free PSA and total PSA. So there is nothing to lose by getting the PHI test but a bit to gain.
Who Should Have PHI test?
This test is used for 2 purposes: (1) screening for prostate cancer among men who have no symptoms related to urinary tract and (2) diagnostic testing to detect prostate cancer in men who have urinary symptoms (such as slow urine stream, frequent urination, blood in urine, etc) that may occur from prostate cancer.
For men who choose to get screening for prostate cancer, PHI certainly provides an advantage over PSA alone. For diagnostic testing, certainly, men should ask their doctor if PHI can be ordered over PSA alone.
There is significant interest from urologists in using the PHI test as it provides better risk stratification than the PSA test or the free PSA ratio does.
Our current tools for risk-stratification of men at risk of prostate cancer which is primarily the PSA test and digital rectal exam are suboptimal.
PSA screening for prostate cancer is highly controversial because of the suboptimal performance of the PSA test.
Based on published studies, PHI certainly provides a significant improvement over PSA alone. However, it is not a panacea. PHI provides improved predictive value compared to PSA, free PSA, and PCA3 but not to the degree that we can rest our efforts to develop a better test.
It is worth noting that PHI incorporates PSA values in the calculations of PHI. PHI is a useful addition to the PSA test alone until we have a better way of risk-stratifying men who are at risk for aggressive prostate cancer.
There is a lot of promising work being done with genetics-based personalized tests for prostate cancer.