Historically, prostate cancer screening has been limited to a PSA (Prostate Specific Antigen) blood test and a prostate examination. The PSA test is extremely useful, but has limitations, including a false positive result. This means that a man can have an elevated PSA without having prostate cancer. PSA can be elevated by benign causes including prostate enlargement and infection, so it is not specific to cancer.
Up until recently, if a patient had an elevated PSA, a prostate biopsy was typically recommended. As discussed in recent blog posts here, MRI now has a vital role in helping us identify potential cancers and improve the accuracy of prostate biopsy.
Ultimately, a prostate biopsy causes anxiety and potential complications including bleeding and infection, and men are often hesitant to undergo the procedure. Some new tests are now available to help better determine which men should undergo a prostate MRI and/or prostate biopsy and which men can potentially avoid further testing.
These tests, called ‘biomarkers’, are innovative new blood tests that help us identify men at high risk vs. those at low risk of having prostate cancer. There are a number of new tests available, but the most promising ones that have been extensively studied and validated are the 4K Score Test and the phi test.
4K Score Test for Prostate Cancer Screening
The 4K Score test is an effective tool that helps limit unnecessary prostate biopsies. It is an assay panel that measures four prostate-specific kallikreins in the blood. This includes the total PSA, free PSA, intact PSA and human kallikrein 2 (hK2). It also factors in the patients age, digital rectal exam results and history of prior biopsy to determine if the patient is at high risk for having aggressive prostate cancer. This allows doctors to only biopsy patients who truly need it.
PHI Test for Prostate Cancer Screening
Another test available for detecting clinically significant prostate cancer is the Prostate Health Index (PHI). This test combines the results of three blood tests (total PSA, free PSA and p2-PSA) to determine a score. The PHI score is three times more specific in detecting prostate cancer than traditional PSA testing, which can substantially decrease the number of unwarranted prostate biopsies.
The 4K Score and PHI test are extremely helpful for some men with an elevated PSA to discriminate those who require a prostate MRI or prostate biopsy. Both tests are available at Sarasota Prostate Care.