The researchers measured EPCA-2 levels in 330 patients, and then divided them into groups determined by their prostate cancer and PSA status. The scientists determined that an EPCA-2 level of 30 or more indicated an elevated risk for prostate cancer, and all of the men with no evidence of the disease -- regardless of PSA levels and any other cancers or benign conditions they may have -- had an EPCA-2 level of less than 30.
Ninety-seven percent of the patients who did not have prostate cancer tested negative in the EPCA-2 test. Seventy-seven percent of men with benign prostatic hyperplasia (BPH), which is often linked to false positives in PSA tests, tested with EPCA-2 levels less than 30.
Ninety percent of study participants who were known to have prostate cancer, and 98 percent who had cancers outside the prostate, showed EPCA-2 levels greater than 30. The test even identified 78 percent of patients known to have cancer despite normal PSA levels.
"This is good news from the diagnostic front," said Mike Adams, a consumer health advocate. "The traditional PSA test has been widely denounced as an accurate measure of prostate cancer, so it's a relief that a more accurate test has emerged. Yet countless doctors around the world continue to rely on the outdated PSA test, which delivers unacceptably high rates of false positives."
The Johns Hopkins scientists said they hope to run bigger clinical trials of the EPCA-2 test, and if these trials generate promising results, the test could be available in approximately 18 months.