Prostate cancer, the most common cancer in men over 50, kills 30,000 a year. One reason is that men don't usually get checked for the disease unless they experience symptoms, such as painful urination. By then, the cancer has spread beyond the prostate in 70% of patients. According to a study in The New England Journal of Medicine, a blood test may soon make it possible to detect the cancer much earlier.
The study, conducted by researchers at Barnes Hospital and Washington University School of Medicine in St. Louis, involved a 10-minute test that measures bloodstream levels of prostate-specific antigen (PSA), a protein produced by the prostate gland. Because PSA levels seem to increase as the disease advances, the test can predict more accurately and earlier which men have the cancer than can rectal exams or ultrasound, the usual diagnostic tests. Without the blood test, up to 40% of the cancers found during the study would have been missed. In patients with mildly elevated PSA levels who had cancer, the disease was localized and therefore curable.
"We'd like to see all men, beginning at age 50, have their PSA levels checked annually as a screening test for prostate cancer," says Dr. William J. Catalona, head of urologic surgery at Washington University.