Using PSA to determine prognosis
An interview with renowned radiation oncologist and researcher Anthony D'Amico, M.D., Ph.D.
The 186,000 or so men likely to be diagnosed with prostate cancer in the United States this year will face a myriad of choices and ask countless questions. "Am I going to die of this disease?" is likely the most frequent query. Until relatively recently, this question was nearly impossible to answer. After all, it wasn't until the late 1980s that testing for prostate-specific antigen (PSA) began; before that, most prostate tumors were detected during a digital rectal examination (DRE), when they were advanced enough to be felt through the rectal wall.
The advent of PSA screening meant that prostate cancer could be detected at an early stage, perhaps more than a decade before it would cause symptoms. But then what? What did a particular PSA test result mean for an individual patient? Did the same numerical PSA score in two different men mean the same thing? Was there any significance to a PSA level that rose quickly instead of gradually? Could doctors use PSA to determine which patients would be the best candidates for surgery? For radiation? For a clinical trial? Was there any way to know who might be cured and who was likely to die of the disease?