Sunday, December 13, 2009

Mammograms, Evidence Based Medicine, Media, Politics,...

In 2002 the researchers of the WHI (Women's Health Initiative) held a press conference to announce to the world the results of their study. This was before any of their peers had a chance to review their results. They told us that they had prematurely halted the study on Hormone Replacement Therapy (HRT) because they had found a significant increase in the risk of heart disease, breast cancer and stroke in the treatment group.
The radio, TV and the internet were ablaze with outraged women that felt betrayed by their physicians who had obviously given them these poisonous pills for years. Many of my patients called our office to inform us that they were stopping their HRT. More than a few however called back a couple of months later to tell me that they were restarting them as life was unbearable with constant hot flushes, night sweats and mood swings.
Fast forward a few years and now these wonderful and informative studies have had a chance to be peer reviewed and a consensus has emerged.
There is no increased risk of the conditions mentioned above for about the first five years after menopause starts. The recommendation now is to only prescribe HRT to alleviate menopausal symptoms and at the lowest dose and for the shortest period of time (usually three to five years). These guidelines for some reason did not grab any headlines. If only we could convince a celebrity to say you could have wonderful sex, all day long if you take HRT according to these recommendations.
It appears that the history is repeating itself. The U.S Preventive Services Task Force (USPSTF) has recently issued its recommendations for screening for breast cancer. You cannot escape the headlines on TV, radio and newspapers. Blogs are also of course full of opinions on the matter. The fact that the American Cancer Society, American College of Obstetricians and Gynecologists and surprisingly! American Society of Radiologists have come out against these recommendations has only added fuel to the fire.
The major changes to the current practice are;
  1. For women aged 40-49 individualize decision to begin biennial (every two years) screening according to the patient's context and values (family history, other risk factors, patient's desire, ...)
  2. For women aged 50-74 screen every two years.
Again, as was the case with the WHI study the USPSTF have done a great job in studying the merits, risks and benefits of a very common screening program. Where this effort has failed, through no fault of its own is that it never had a chance to be appropriately peer reviewed and a consensus to be reached. This should have been done before the media had a chance to make a mockery of it and the Congress to feel obliged to step in.
A screening program must meet the following criteria;
  1. The disease in question should constitute a significant public health problem, meaning that it is a common condition with significant morbidity and mortality.
  2. The disease should have a readily available treatment with a potential for cure that increases with early detection.
  3. The test for the disease must be capable of detecting a high proportion of disease in its preclinical state, be safe to administer, be reasonable in cost, lead to demonstrated improved health outcomes, be widely available, as must the interventions that follow a positive result.
Adequacy of a screening test should not be based on anecdotal evidence or questionable expert opinions. Everyone can remember an uncle or a grandfather that lived to be ninety despite smoking a pack a day. It doesn't make smoking safe. This brings me to my favorite Hippocrates quote;
"There are in fact two things, science and opinion the former begets knowledge, the latter ignorance."
My patients have started asking me about these new recommendations and for now I'm telling them that I'll wait for the dust to settle and for knowledge to overcome ignorance.

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