New blood test for prostate cancer improves diagnostic accuracy August 5, 2014
A new blood test for prostate cancer is improving the accuracy of diagnoses and may even reduce the frequency of false positives and unnecessary biopsies.
The Prostate Health Index (PHI) test could fill the diagnostic gap clinicians currently have when screening for prostate cancer. By using three different prostate-specific markers, the test is more accurate in detecting prostate cancer than the current prostate specific antigen (PSA) test.
Over the last several years, there has been much debate in the realm of over-screening, over-diagnosis, and the inaccuracy of diagnostic tools in prostate cancer. This test greatly improves this dilemma by giving clinicians more accurate information on what an elevated PSA level might mean, and the probability of finding cancer from a biopsy.
What is wrong with our current standard of testing? Simply put, PSA is not specific to prostate cancer. Elevations can be seen with any prostatic disease including infection, benign prostatic hyperplasia and prostate cancer.
Here are some other factors which can affect PSA levels:
- Prostate biopsy or massage: Both can temporarily affect PSA level
- Race: African-Americans have higher baseline PSA levels than Caucasians
- Prostate volume: Increase in PSA level of 4 percent for every ml of prostate volume
- Age: Older men have higher baseline PSA
- Certain medications: 5-alpha reductase inhibitors are used to treat BPH and male-pattern baldness and can decrease PSA by 50 percent after 6 months
As you can see, physicians and patients alike are faced with challenges with the current standard for prostate cancer diagnosis, which is based on the fact that men with higher levels of the PSA protein are more likely to have prostate cancer. This lack of specificity can lead to false‐positives for cancer and ultimately unnecessary biopsies.
The PHI test promises to better distinguish prostate cancer from non-cancer disorders. This is done by using a process that evaluates three different PSA markers to determine the likelihood of cancer in patients with elevated PSA levels.
Hopefully, the accuracy of this test will decrease the need for biopsy in many men who test positive for elevated PSA levels in order to get a dependable diagnosis.
For more information about prostate cancer or diagnostic tools, visit Dr. Samadi’s website ProstateCancer911.com.