Why early detection of cancer is not always good

Amidst the recent cancer stories in the media and the news on breast MRIs, comes this timely article from Orac. Required reading:

The bottom line is that the ever-earlier detection of many diseases, particularly cancer, is not necessarily an unalloyed good. As the detection threshold moves ever earlier in the course of a disease or abnormality, the apparent prevalence of the disease increases, and abnormalities that may never turn into the disease start to be detected at an increasing frequency. In other words, the signal-to-noise ratio falls precipitously. This has consequences. It leads, at the very minimum to more testing and may lead us to treating abnormalities that may never result in disease that affects the patient, which at the very minimum leads to patient anxiety and at the very worst leads to treatments that put the patient at risk of complications and do the patient no good.

Marc Siegel should read this and maybe he’ll learn a thing or two.