Monday, September 10, 2012

Screening Dilemmas


A recent blog by Melinda Beck in the Wall Street Journal discusses the issue of whether there is "Too Much Breast Cancer Treatment?".  The blog is partially based on a study from the Annals of Internal Medicine in April , about the over diagnosis of breast cancer.  It brings up a difficult problem for all of medicine and for all health professionals.  What do you do if there is population data that suggests, as that article does, that many people who undergo treatment are not going to benefit and may actually suffer due to the risk and side effects of the treatment, yet for any specific individual, it is virtually impossible to tell who fits into the group of those people who truly need and benefit from the treatment versus who is in the group who will not benefit from the treatment?  And how do you truly understand the choice involved when the risk of not treating is catastrophic? 

In some ways, we are talking about the basics of screening tests.  A good screening test tends to be highly sensitive.  Unfortunately, this can mean, and often does mean that is it not very specific.  In other words, it is designed to have very few false negatives even at the risk of having a lot of false positives so this article on screening for Breast Cancer may be accused of belaboring the obvious (although it tends to not be obvious to many in the population and in our legislative bodies who think you can always have high sensitivity and high specificity in screening tests).  We often tend to make a societal decision to avoid the risk of individual catastrophe by putting up with the higher costs and the relative risks of pursuing all of those false positives with more tests and treatments that have their own risks.  In the past year, the debate over the recommendation on the age of initiating mammography for breast cancer screening has remained in the public awareness as that societal decision on the avoidance of risk was made differently by the US Preventive Services Task Force which recommended starting screening at age 50 while the American Cancer Society suggested remaining at a screening start age of 40. 

The real challenge to health professionals is to inform people without panicking them and without biasing them one way or another.  The judgement of the relative risks and benefits should properly be made by an individual and not by the society as a whole however it should be made with full knowledge.  People need to know that a screening test may leave them with a “positive” result that is ultimately false that leads them down a path that can create other problems.  At the same time, they also have to know that missing early stage disease, such as breast cancer, can make treatment more difficult and less likely to be ultimately successful.  These are not easy messages to give as they are more nuanced than just saying, “have the test” or “don’t have the test”.  Health professionals should be present to help people make their own decisions after they have all the facts and are as calm as possible when they make those decisions not to force their own values or even society's values on those individuals.