FDA has. A new type of PSA test was approved. for prostate cancer. The company that developed it, Beckman Coulter, claims the test could help doctors do a greater job of telling the difference between prostate cancer and benign prostate conditions. In theory, a more cancer-specific PSA test would scale back unnecessary biopsies.
The test, called the Prostate Health Index (PHI), has been available in Europe since 2010. With FDA approval, it ought to be available within the US later this summer. The PHI combines measurements of three forms of prostate-specific antigen (PSA), a protein produced by the prostate gland. The FDA approved the PHI test to be used in men age 50 and older with a traditional total PSA reading between 4.0 and 10 nanograms per milliliter (ng/mL), and who had a digital rectal exam. There were no signs of cancer.
A PSA result between 4 and 10 leaves a person in a gray zone: It could indicate prostate cancer, or it may very well be quite a lot of other, less scary things, including an infection or an enlarged prostate gland. In men with PSA levels within the 4.0 to 10 range, a biopsy confirms cancer about 25% of the time. This unnecessarily exposes the remaining 75% of men to discomfort, anxiety and risk of infection and/or bleeding.
“It's a really slippery slope,” says Dr. Garnick. “Unless studies show that more significant cancers are identified and treated than with standard screening, and that such treatment leads to better outcomes, its use is very limited.” Caution ought to be exercised.”
Another cancer-specific test?
The PHI test combines measurements of total PSA, free PSA (a form that circulates within the bloodstream with other proteins) and a subcategory of free PSA called pro-PSA (sometimes called p2PSA). . Some research suggests that pro-PSA is more closely related to prostate cancer than total or free PSA.
Doctors can use the PHI rating to find out the likelihood that a biopsy will detect prostate cancer. According to clinical data Beckman-Coulter submitted to the FDA, using the PHI rating could prevent about one in seven unnecessary biopsies while still detecting 95 percent of cancers. In comparison, using free PSA testing alone could prevent one in ten unnecessary biopsies.
Some research also suggests that there could also be a link between Pro-PSA levels and the aggressiveness of prostate cancer. Additional studies are needed to substantiate this.
Could the brand new test worsen overdiagnosis?
About half of all prostate cancers diagnosed with PSA testing won’t ever threaten health or longevity without treatment. This signifies that half of men treated for PSA-detected prostate cancer suffer uncomfortable side effects from the treatment, including impotence and incontinence, without gaining any profit. Because of the widespread use of PSA testing and increased treatment of low-risk prostate cancer, the federally appointed US Preventive Services Task Force Recommends against routine PSA testing. In men without signs or symptoms of prostate cancer.
Unless the PHI test can discover high-risk cancers, Dr. Garnick says, “it can actually lead to overdiagnosis problems and overtreatment of indolent prostate cancers that have normal PSA levels.” testing has not been shown to be useful.”