In the age of evidence-based medicine, one might think a question such as “When should a woman have a mammogram?” would be easy enough to answer. But unfortunately this is not a simple question and mammogram guidelines can be confusing. The answer depends on what outcomes you measure. Various agencies and organizations value different outcomes, and so we get inconsistent recommendations regarding when to start mammography, how often to get mammograms, and even when to stop getting mammograms.
What do I mean by different outcomes? Are you using mammography to save as many lives as possible? Or are you trying to save healthcare dollars? Sadly, these endpoints might be in opposition to one another. Should we maximize early diagnoses of precancerous changes and stage 0 breast cancer? Or try to avoid treating women with indolent disease that will never metastasize? These aims can be in direct conflict with each other at times.
The US Preventative Service Task Force has released a series of mammogram guidelines in recent years which have gotten significant media attention for their controversy. They recommended mammograms start at age 50 in contrast to most other organizations who suggested starting at 40. The reason for this recommendation? The USPSTF used a statistical model that optimized “efficiency” as an endpoint. Their own data analysis showed 15% mortality reduction for women aged 40-49 screened with mammograms. But if you value efficiency above all, this improved mortality was not worth the number of mammograms required to achieve it.
As a member of the American Society of Breast Surgeons, I use ASBrS screening mammogram guidelines. This process begins with a risk assessment to tailor the screening plan to the individual. ASBrS recommends a risk assessment performed by a physician for all women over age 25. Ladies found to have an average risk for breast cancer (12% lifetime risk) should begin having mammograms yearly starting at age 40.
For high risk individuals (over 20% lifetime risk) the plan may include starting screenings earlier than 40, using breast MRI, and possibly genetic testing for cancer-causing gene mutations. For a woman with dense breast tissue, a genetic mutation, or prior abnormal biopsy, the screening plan is further customized.
In the age of evidence-based medicine, we must look at what evidence is being used to make a recommendation and what statistical model is being employed. I trust mammogram guidelines that value early diagnosis and increased survival over health care dollars saved.
