By Michael Millenson

My father is in his late 80s, so it’s not surprising that he’s had a brush with prostate cancer. That’s why the 
Los Angeles Times’ obituary of Donald F. Gleason, the Minnesota pathologist who invented the “Gleason score” for characterizing cancerous growths in the prostate, caught my eye. Gleason died at the age of 88 from a heart attack.The Gleason score is now used almost universally to predict the likely outcome of prostate cancer. But the obituary provided unexpected insight into yet another instance of an agonizingly slow spread of evidence-based medicine for a common and deadly condition and unavoidably raised the question about diffusion of innovation today.Gleason had been an unknown, junior-grade pathologist in 1962 when he was approached by his hospital's chief of urology to develop a standardized rating system for determining the grade of prostate tumors; that is, a measure of how far they had progressed and their likely course. At the time, the obit noted, “each pathologist pretty much used his own system, which made comparing research results among different groups nearly impossible.”

Through a fascinating process that ignored conventional medical wisdom, Gleason came up with a tumor grading process that was shown by five representative pictures. (He knew pathologists liked to look at pictures.) Grades on two common types of tissues in a tumor were combined for a Gleason score that turned out to have a “surprisingly strong correlation” with patients' death rates. That was in 1966.

As the obit delicately put it, “the Gleason scale was slow to catch on, but in 1987, seven of the leading authorities in urology and urological oncology sent a letter to the editor of the Journal of Urology urging that it be applied uniformly in all publications on prostate cancer. Their recommendation was adopted and the scale quickly came into wide use.” Forty years after its discovery, the Gleason score remains the “gold standard.” I have tried to imagine my father’s treatment decision without the Gleason scale to provide objective predictive information (so far, he’s fine). And I can’t help but suspect that Gleason’s breakthrough innovation was slow to spread because it was low-tech, didn’t make large profits for any individual or corporation and challenged the paradigm of each individual pathologist relying on his unfettered clinical judgment. Has the culture of medical practice changed enough over the last couple of decades to prevent the same thing from happening today? Perhaps. You be the judge.