New Test Spots Early Prostate Cancer

A new blood test that detects early prostate cancer antigen (EPCA) promises to be a "powerful complement" to standard prostate specific antigen (PSA) testing for identifying patients with prostate cancer, researchers report. Dr. Robert H. Getzenberg from Johns Hopkins Hospital in Baltimore predicts, "once this test is refined and approved for general use, it will have an impact on the detection and treatment of prostate cancer." The traditional two-step approach of PSA testing and digital rectal exam allows doctors to identify tumors early, at a potentially curable stage. But PSA testing has its drawbacks -- it occasional gives high values in the absence of prostate cancer and low levels when prostate cancer is present, Getzenberg and colleagues note in the journal Cancer Research. Getzenberg, along with colleagues at the University of Pittsburgh determined EPCA's value as a marker of prostate cancer by testing plasma samples from 12 patients with prostate cancer, 2 with non-cancerous prostatitis, 9 with bladder, colon or renal cancer, 7 with spinal cord injuries and 16 healthy individuals. EPCA levels were high in 11 of 12 prostate cancer patients (92 percent) and low in all of the healthy individuals. EPCA was also highly specific for prostate cancer. Only two bladder cancer patients and none of the other patients had high EPCA levels, suggesting that the EPCA test was correct 94 percent of the time. "This new blood test, when coupled with PSA screening, may help reduce the number of both unnecessary biopsies and undetected prostate tumors," Getzenberg said. This study was supported by Tessera, Inc., which has a license agreement with the University of Pittsburgh regarding the EPCA test.