Next to skin cancer, prostate cancer is the most common form of cancer in the United States. However, many cases of prostate cancer are overdiagnosed due to the inefficiency of the Prostate-specific antigen, or PSA test.
Last week, Oxford Biodynamics announced the release of its EpiSwitch Prostate Screening (PSE) blood test after successful laboratory validation. The United Kingdom-based biotechnology company says its device improves the predictive accuracy of current PSA tests to 94%.
The U.S. National Institute of Health notes PSA tests can help detect small tumors. Because of this, many of the small tumors detected are likely to grow. Detecting these forms of tumors is known as "overdiagnosis" which leads to "overtreatment."
According to the CDC, false positive results for prostate cancer can lead to unnecessary tests, like a biopsy of the prostate. Possible side effects of biopsies include pain, infections, and bleeding. The CDC says older men are more likely to have false positive test results. The CDC reveals that overtreatment exposes individuals to uncalled-for complications associated with prostate surgery and radiation therapy.
Possible side effects of prostate cancer treatment listed by the CDC:
- Urinary incompetence: Nearly one out of every five men who have prostate surgery lose the ability to manage their bladder.
- Erectile dysfunction: About two of every three men who have prostate surgery become impotent. Meanwhile, half of men who receive radiation therapy become impotent.
- Bowel troubles: About one in every six men who have radiation therapy are susceptible to the sudden and controllable urge to have a bowel movement.
False-positive results are extremely common with PSA screening, the NIH says. Only about 25% of men who receive a prostate biopsy due to high PSA levels are found to have prostate cancer after the biopsy test is concluded. Over one million American patients each year undergo a prostate biopsy.
The new Prostate Screening EpiSwitch or PSE test developed by Oxford Biodynamics is run alongside a standard PSA test to predict the presence or absence of prostate cancer. Oxford Biodynamics’s product has been validated in its Clinical Laboratory Improvement Amendments-certified testing laboratory in Frederick, Maryland. The PSE test is now available for order. Test results take a maximum of five days after a blood sample is received.
Phillip Pierorazio, Section Chief of Urology at Penn Presbyterian Medical Center and Professor of Surgery at the Hospital of the University of Pennsylvania, hopes the PSE test will have an immediate impact.
"Although the traditional PSA has demonstrated clinical utility in prostate cancer screening and monitoring, it also has limitations that are well-described," Pierorzio said in a release. "A more sensitive and specific test would have the potential to increase diagnostic accuracy and address some of the current challenges with prostate cancer screening."
PSE blood test contains 94% predictive accuracy, 97% specificity, and 86% sensitivity to assess the risk of prostate cancer in men. PSA tests possess 55% accuracy, 53% specificity, and 64% sensitivity. Oxford BioDynamics CEO John Burrows tells Healthnews the PSE test will reduce the amount of false positive test results.
"Unfortunately, until now, there has been no way to tell who is a false positive. PSE has a positive predictive value of 94%, so approximately 1 in 20 will be false positive — a massive improvement from 3 of 4," Burrows said. "The PSE test combines the PSA score with five epigenetic biomarkers (chemical markers on your DNA) to predict the presence or absence of prostate cancer. For each individual, the EpiSwitch technology captures personal epigenetic biomarkers that represent a systemic fingerprint of specific regulatory network changes associated with prostate cancer."
New forms of prostate cancer screening like the PSE test are desperately needed. The CDC says all men are at risk of prostate cancer, and 13 out of 100 U.S. men will have prostate cancer in their lifetime. In 2019, 224,733 new prostate cancers were reported in the U.S. along with 31,636 deaths.
The CDC notes Black men are more likely to be diagnosed with prostate cancer, and are twice as likely to die from the disease when compared to other male races. Individuals who have had a family diagnosed with prostate cancer are more likely to acquire the disease.