From the History Books: Blood Test Gives Urologists a New Way to Detect Prostate Cancer
The prostate-specific antigen (PSA) test is one of the most familiar of urology's milestones. Millions of men have benefited from early prostate cancer detection because of this revolutionary—albeit somewhat controversial—blood test. The research that produced this simple tool is relatively recent. Before 1986, when the Food and Drug Administration approved the PSA test for monitoring prostate cancer, no blood test existed for the disease.
In the past the digital rectal exam was the only screening available and would detect cancer often when tumors were too advanced for cure. Prostatic acid phosphotase (PAP) proved to be a sensitive blood-serum marker for advanced prostate cancer, but did little for early detection since it missed localized tumors.
So there's little surprise that the discovery of prostate-specific antigen, an enzyme manufactured by the prostate and secreted in excess into the bloodstream when cancer is present, would turn into such a valuable screen for