Our brain and mammograms
The utility of mammograms in improving survival from breast cancer suffered another blow. From a rational point of view, the idea that women without any risk factors will benefit from regular mammograms is dead and buried, 6 feet under with the coffin nailed shut. And yet, many women feel a strong pull to get a mammogram. I think there are generally two reasons. First, we humans are spectacularly irrational, emotionally driven animals. I can not do any better than Chris Mooney did in a Mother Jones article in explaining this. So I strongly recommend that you check out Chris’ article: http://www.motherjones.com/politics/2011/03/denial-science-chris-mooney. In brief, put an emotional viewpoint in the ring with a logical laying out of the facts, and the emotional viewpoint will score a knock-out in no time flat. Regardless of their content or source, facts and reason don’t stand a chance against emotionally held beliefs.
The second reason that women still want mammograms despite a complete lack of evidence for their efficacy in improving survival is that most women have no way to make sense of mammograms’ lack of efficacy. This essentially puts emotion in an uncontested fight. There is no logical framework within which to understand the evidence regarding mammograms. So here is a framework. Cancer cells have a natural history. They are in a competition with other cells for the body’s resources. Some cancer cells are successful and consequently wreak havoc. But many other cancer cells lose out and die. We want to learn much more about cancer cells’ life histories. Hopefully one day we can predict which cancer cells will die out on their own (no treatment needed) and which are bound for success (treatment needed). At present mammograms do a poor job of distinguishing between these two types of cancer cells. Consequently the mammograms are crying wolf a lot!! So many of the tumors that are “caught” by mammograms are not bound for success. Even though they would have gone on to nothing, these tumors are treated once they are found. And there is the added risk that by bothering cancer cells with surgery or radiation, we change their course, tickling a cancer cell may transform it from something innocuous into something malignant. By the way if you are interested in the life-and-death evolutionary struggle of cancer cells, check out Evolution and Medicine by Robert Perlman (OUP, 2013).
Now join me in an experiment. Leave a comment and let us all know if having the above framework changes your mind at all. What did you think about mammograms and about the evidence that they don’t help survival before reading this post? What do you think now? Will you switch from getting regular mammograms?