What If What You ’Survived’ Wasn’t Cancer?
http://www.bloomberg.com/news/2013-08-18/what-if-what-you-survived-wasn-t-cancer-.html
You’re feeling fine when you go for your annual physical. But your mammogram looks a little funny, or your PSA test is a little high, or you get a CT lung scan and a nodule shows up. You get a biopsy, and the doctor delivers the bad news: You have cancer. Because you don’t want to die, you agree to be sliced up and irradiated. Then, fortunately, you’re pronounced a “cancer survivor.” You’re glad they caught it early.
But maybe you went through all that pain for nothing.
For decades, the reigning theory has been that the earlier a cancer is spotted and treated, the less likely it is to be lethal, because it won’t have time to grow and spread. Yet this theory infers causality from correlation. It implicitly assumes that cancer is cancer is cancer, even though we now know that even in the same part of the body,
cancer is many different diseases -- some aggressive, some not. Perhaps people survive early-stage cancers not because they’re treated in time, but because their disease never would have become life-threatening at all.
This isn’t just logical nit-picking. Thanks to widespread screening, the number of early-stage cancers identified has skyrocketed. In many instances -- including types of breast, prostate, thyroid and lung cancers --
more early diagnoses haven’t led to proportionate decreases in mortality. (New drugs, not early detection, account for at least two-thirds of the reduction in breast-cancer mortality.) The cancers the tests pick up aren’t necessarily life-threatening. They’re just really common. So more sensitive tests and more frequent screening mean more cancer, more cancer treatment and more cancer survivors...In a well-intended effort to save lives, the emphasis on early detection is essentially looking under the lamp post: Putting many patients who don’t have life-threatening diseases through traumatic treatments while distracting doctors from the bigger challenge of developing ways to identify and treat the really dangerous fast-growing cancers.
“Physicians, patients, and the general public must recognize that overdiagnosis is common and occurs more frequently with cancer screening,” argues a recent JAMA article by the oncologists Laura J. Esserman (a surgeon and breast-cancer specialist), Ian M. Thompson Jr. (a urologist) and Brian Reid (a specialist in esophageal cancer). They argue for limiting the term “cancer” to conditions likely to be life-threatening if left untreated.
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