Blood test combines PSA and epigenetics for diagnosing prostate cancer with 94 percent accuracy
CANCER DIGEST – Feb. 17, 2023 – Researchers have developed another new blood test that detected prostate cancer with 94 percent accuracy in a small study. The results appear in the Jan. 29, 2023 journal Cancers.
The test, developed by Oxford Biodynamics in collaboration with the University of East Anglia in the UK, combines the current PSA (prostate specific antigen) test with an epigenetic test that detects cancer-specific chromosome conformations.
Analyzing chromosome conformations uses molecular biology methods to analyze the organization of chromatin (a complex of DNA and protein) within a cell. In this case the EpiSwitch test, as it is called, detects chromosome structures linked to prostate cancer.
In the pilot study the researchers analyzed blood samples from 147 men, 109 of whom were enrolled in a prostate screening study, but did not have cancer, and 38 samples from men with established prostate cancer. Using the standard PSA test resulted in a positive predictive value (PPV) of .14 and a negative predictive value (NPV) of .93. Using the EpiSwitch test alone resulted in a PPV of .91 and NPV of .32. When they combined the PSA with the EpiSwitch test (PSE) the PPV was .92 and NPV of .94.
"Only about a quarter of people who have a prostate biopsy due to an elevated PSA level are found to have prostate cancer," Dimitry Pshezhetskiy, research fellow at Norwich Medical School and lead author of the study said in a press release. "When tested in the context of screening a population at risk, the PSE test yields a rapid and minimally invasive prostate cancer diagnosis with impressive performance. This suggests a real benefit for both diagnostic and screening purposes."
The test will need to be evaluated in larger screening trials before its accuracy is defined for clinical use. Click here for related article.