NEW TEST FOR PROSTATE CANCER MAY ELIMINATE MANY BIOPSIES

A new prostate cancer test could eliminate up to 75 percent of unnecessary biopsies while effectively screening for the deadly disease, a study says.

"If further studies confirm our findings, the test may make it easier for physicians to determine which patients are likely to have cancer and need follow-up biopsies," said Dr. William J. Catalona, lead investigator for the study at the Washington University School of Medicine in St. Louis.Prostate cancer is the nation's second-leading cancer killer of men. The American Cancer Society predicts it will strike 244,000 American men this year and kill 40,400.

A current prostate cancer blood screening test detects all types of prostate-specific antigen (PSA), a protein produced by the prostate. Elevated levels are a possible indicator of cancer. But too often, the test incorrectly indicates cancer, making a biopsy necessary.

Only one in three men with elevated PSA levels who undergo biopsies are found to have cancer. That's because a noncancerous condition called benign prostatic hyperplasia (BPH), which is commonly found in older men, can also raise PSA levels.

Catalona, who pioneered PSA testing for prostate cancer, said the new test could help doctors distinguish between prostate cancer and BPH by isolating so-called "free-floating" PSA. For reasons doctors don't fully understand, men with prostate cancer have significantly lower levels of "free-floating" PSA compared with men with BPH, Ca-ta-lo-na said.

The new test could eliminate up to 75 percent of unnecessary biopsies while still detecting 90 percent of prostate cancers, Catalona said.

Several other recent studies have suggested that the free-PSA test may be a useful screening tool, but Catalona's is the first to show that it can accurately detect cancer in a problem group of men - those with only slightly elevated PSA levels.

A prostate biopsy, which costs from $1,000 to $2,000, involves inserting a needle into the walnut-sized gland to withdraw cells, which are analyzed for cancer under a microscope.

The cost of the new blood test hasn't been determined, but existing tests for prostate-specific antigen run about $50 to $100.