Our patient today had a PSA of 7.4. He is a 67 year old Caucasion male with no other medical issues other than episodic high blood pressure. He does report some mild urinary symptoms mostly involving going to the bathroom frequently but his urine stream is normal and he has no incontinence or dribbling.
He has had PSA testing in the past. At one point it was 7.1 but after he saw a holistic practitioner it decreased to 4.5. Approximately 6 months later it was 7 again and his primary care doctor thought it was worth evaluating further. He did not want a biopsy and so had a prostate ultrasound performed and an examination by a Urologist. His prostate was smooth and the ultrasound was benign so it was considered appropriate to just watch him.
The new PSA was 7.4 which does represent an increase from previous. In addition, his urinary symptoms has worsened but not drastically so. He still had a normal stream but had increased frequency in compared to before.
For a better risk assessment, we performed a Total and Free PSA. Many physicians are not familiar with the Free PSA.
In men over 50 with an elevated Total PSA, the %Free PSA gives an estimate of the probability of prostate cancer
Our patient had a Total PSA = 7.4 and a %Free PSA – 22%. In this case, the ideal %Free PSA should be over 25%. The lower the %Free PSA the greater the greater the probability of cancer. Here is a table that shows the Estimated Probability of prostate cancer.
PSA(ng/mL) Free PSA(%) Estimated(x) Probability of Cancer(as%) 0-2.5 (*) Approx. 1 2.6-4.0(1) 0-27(2) 24(3) 4.1-10(4) 0-10 56 11-15 28 16-20 20 21-25 16 >or =26 8 >10(+) N/A >50 Given that our patient's Total was in the 7 range and the high Free PSA, the probability of cancer is low but still significant at 16%
Here is a nice graph from Quest: showing our possible decision tree.
This patient had a normal rectal examination so the liklihood of cancer based on the testing is still low but significant. The next options are to refer for a biopsy, which he did not want, wait to re-test in 3-6 months to see how the numbers may change or to see if we can’t further risk stratify.
If we want to further risk stratify then we can consider using the Prostate Health Index (PHI).
This patient, like many, fall into that category that often result in a biopsy but don’t have cancer. See our image above. Of course, one never knows and that is why the biopsy is performed because who want to be the statistic that ends up with prostate cancer.
To help with this decision, researchers looked for an alternative biomarker which led to the discovery of the PHI. PHI offers greater specificity in identifying patients that truly need a biopsy.
Phi is the only FDA approved blood test that is 3 X more specific than PSA alone.
The phi combines the use of another biomarker called p2PSA which is an isoform of free PSA that is the most prostate cancer specific biomarker found. When p2PSA is used with the total PSA, and free PSA, the diagnostic accuracy improves to 71%
If you are like our patient who falls into this gray zone area and are concerned about getting a biopsy. Please call us at 352-235-9636 or Toll Free at 855-474-8522
or Schedule an Online Diagnostic Consultation