2/12/2014

In today’s New York Times on the front page there is an article about a long-term Canadian study involving mammographic screening for breast cancer. It looked at over 90,000 women randomized to get mammographic screening vs. those who only had a breast exam by a nurse without mammography. It lasted 25 years. It was published in the British Medical Journal. It found that there was no difference in deaths from breast cancer in either group (about 1 death per 90 women enrolled over the 25 year period). While I have not yet seen the full article I feel compelled to make some observations.

 

  • Clearly breast cancer is not “one disease”. Some forms are clearly more virulent than others.

 

  • In this study, the death rate in the non-screened group was probably lower than it might have been because of improved treatments that we now have even for later stage breast cancers that present because they are large enough to feel.

 

 

  • In the screened group, my biggest concern is that people (i.e. patients, the government) think mammography is a “laboratory test”. What do I mean? If I order a blood count on my patient and she goes downstairs and has blood run through a machine called a Coulter Counter that is well calibrated, and let’s say her blood count is 39.4, and I were to send her for a similar test at Hackensack Hospital with a well calibrated machine perhaps it would be 39.7, but it would not be 25 or 48. Those are highly reproducible laboratory tests. Mammography is only as good as the equipment employed and the people performing and interpreting the study. I know little about the Canadian system of health care, but I guarantee that the 45,000+ women were not getting the quality of mammographic screening that most of my patients are receiving. The mammography facilities that I recommend do not simply have a technician do a study and then later have a physician come by and read images, and then having to decide if it is necessary to call the patient back for further evaluation. The best facilities (the ones I recommend) do not let the patient leave until all issues have been reconciled and this often involves a spot film or compression film or ultrasound when necessary. Most good facilities will have a “double read” (two physicians) and some even include a clinical breast exam and the doctor speaking to the patient. I have no doubt that some of the deaths that occurred in the screened group in this study were “false negative” studies where people with early cancers went undetected. That has not been my experience when patients of mine are in the hands of top mammography facilities.

 

This is not unlike my concerns about those who feel that transvaginal ultrasound cannot detect early ovarian cancer. Transvaginal ultrasound is even more operator and equipment dependent than mammography. So while the United States Preventative Services Task Force (USPSTF) may recommend against routine screening of ovaries that recommendation is based on very flawed population data. I take care of patients myself, one at a time, and perform my own transvaginal ultrasound exams with top-of-the-line equipment.  

 

So…bottom line is do not consider changing your mammographic screening…unless the facility you use is not one of the highest quality.

 

As usual, if you have any issues or questions do not hesitate to call. I remain yours in health.