The New York Times reports on a couple of head-scratching studies:
The PSA blood test -the screening test for prostate cancer -saves few if any lives and exposes large numbers of men to risky and unnecessary treatment, two large and rigorous studies have found.
The findings raise new questions about the rapid and widespread adoption of the test, which measures a protein released by prostate cells. It was introduced in 1987 and quickly became a routine part of preventive health care. Experts debated its value, basing their views on data that often involved statistical modeling and inferences.
Now, with the new data, cancer experts said men should carefully consider the test’s risks and benefits before deciding to be screened. Some may decide not to be screened at all.
Dr. Kenneth Tokita of the Cancer Center of Irvine will join me today to discuss these studies. Dr. Tokita is one the preeminent prostate cancer specialists in southern California. I have a number of friends who have been diagnoses with prostate cancer in the past few years, each of whom would never have received their early diagnosis and completely successful treatments without the PSA test as part of their regular medical exams. The article summarizes the findings this way:
The reason screening saved so few lives, cancer experts say, is that prostate cancers often grow very slowly, if at all, and most never endanger a man if left alone. But when doctors find an early-stage prostate tumor, they cannot tell with confidence whether it will be dangerous so they usually treat all early cancers as if they were life-threatening.
As a result, the majority of men, whose early-stage cancers would not harm them, suffer serious effects of cancer therapy but get no benefit. Others, with very aggressive tumors, may not be helped by screening because their cancer has spread by the time it is detected.
While it may make sense to forego treatment if medicine develops the ability to distinguish between deadly and non-deadly cancers, the MSM should be very careful about broadcasting a message that cancer screening is an unnecessary luxury.