June 1 (HealthDay News) -- A new blood test greatly reduces false-positive results in prostate cancer screenings and, when used in combination with a prostate-specific antigen (PSA) test, could prevent many unnecessary biopsies, U.S. researchers say.

Their two-year study of 484 men found that using a six-gene molecular test with a PSA test accurately detected prostate cancer more than 90 percent of the time and eliminated most of the false-positives from the PSA test alone. Earlier research has found that the PSA test is 60 percent to 70 percent accurate in detecting cancer.

"These findings are very encouraging and suggest that this new test could spare tens of thousands of men from undergoing an unnecessary biopsy," study author Dr. William K. Oh, clinical director of the Lank Center for Genitourinary Oncology at the Dana-Farber Cancer Institute in Boston, said in a news release from the organization.

"However, until we can verify our findings, it is important to recognize that the PSA test, despite its limitations, is still the best test available for diagnosing prostate cancer at this time," said Oh, who was to present the findings Sunday at the American Society of Clinical Oncology annual meeting, in Orlando, Fla.

The study received funding from Source MDx, which developed the new blood test. Oh and his colleagues are planning a larger clinical trial of about 1,000 men to verify the findings.

Being able to more accurately detect prostate cancer is important. Men who are found to have elevated PSA levels in screening tests are often referred to a prostate biopsy, a painful procedure with some risk of complications. Nearly two-thirds of prostate biopsies don't find any cancerous cells, according to the news release.

SOURCE: Dana-Farber Cancer Institute, news release, May 28, 2009