Test detects aggressive prostate cancer

CHICAGO, April 7 (UPI) -- A new prostate specific antigen test to screen for prostate cancer is more accurate in detecting more aggressive prostate cancer, U.S. researchers say.

Lead investigator Dr. William Catalona, director of the clinical prostate cancer program at the Robert H. Lurie Comprehensive Cancer Center of Northwestern University, says the current test produces a high number of false positives and unnecessary biopsies, and possible over-detection and overtreatment of cancer that never would have caused suffering or death.

"This new test is more specific and accurate than the currently available blood tests for early prostate cancer detection," Catalona says in a statement. "This will focus on the detection of more life-threatening prostate cancers and reduce unnecessary biopsies in men 50 years of age and older."

The researchers tracked 900 patients from 10 sites, including Northwestern and found the new test -- the Pro-PSA -- is particularly useful for patients with a normal prostate exam whose PSA is 2 to 10, a range considered the diagnostic gray zone because most men with higher levels have prostate cancer and most men with lower levels do not.

The Pro-PSA test measures a more specific PSA subform called (-2) Pro-PSA and it is more accurate, Catalona says.

"The logic behind the formula is that the higher the Pro-PSA and the total PSA and the lower the free-PSA, the more likely the patient has aggressive prostate cancer," Catalona says.