2007年VOA标准英语-Researchers Find Better Blood Test for Prostate（在线收听）
Washington
01 May 2007
Prostate cancer is one of the most common cancers for men in the developed world. Some 400,000 new cases are likely to be diagnosed this year in the United States and Europe, and close to 90,000 men are expected to die from the disease. As men live longer in developing countries, the numbers of men getting this cancer are expected to increase. VOA's Melinda Smith narrates this report on a new test to diagnose prostate cancer.
Doctors urge men over 50 to have a yearly blood test for prostate specific antigen, or PSA.
High or rising levels of PSA are warning signs for prostate cancer. But the test is not always accurate, so many men undergo a painful second test, a biopsy of the prostate.
Professor Robert Getzenberg says there is just one problem. "Right now we're biopsing [performing biopsies on] about six men to find one that has prostate cancer. So what we want to do is limit our focus on those that really do have the disease."
Besides false positives, PSA tests can also miss some cases of cancer. The standard PSA blood test measures a chemical produced in the prostate. The new test measures a chemical made only by cancer cells in the prostate. Professor Getzenberg and his research team found that the new test was at least 94 percent accurate.
Larger clinical trials are planned that could make the new test available to the public in approximately a year and a half, something patient Jay Weiss would welcome. "I certainly did not look forward to the second biopsy, much less the third one."
Getzenberg said the test also can tell if the cancer is confined to the prostate or if it has spread.