Mammographic Screening for Breast Cancer – Who, When, and Why?
Mammography for screening of women older than 35-40 years of age was considered a no-brainer for many years and was advocated by all of the major support groups. Screening mammograms have always been felt to decrease the chances of dying from breast cancer by as high as 30% and when state governments have implemented stronger screening programs after approximately 10 years, mortality from breast cancer has decreased. Breast cancers discovered by mammography are smaller and of lower stages when compared to those cancers discovered on examination by patients or their doctors.
Recently more scrutiny has been applied to routine screening and its opponents have become more vocal. The US Preventative Services Task Force (USPSTF) created a huge stir by suggesting the literature recommended screening with mammography for women between the ages of 50 and 74 be changed to every two years, selective screening before age 50 years, and no obvious benefit for older women. Switzerland upped the ante by not recommending mammographic screening at all (although I’ve heard it is still common for women there to do so).
The problem with mammograms (other than the discomfort) is that they are only 80% sensitive at finding breast cancers and often recommend biopsy for abnormalities that are not cancer (benign). Every biopsy recommended produces a cascade of fears and emotions that can have lasting effects often leading some women to forego any type of screening in the future. Mammography also exposes women to radiation which we know predisposes women to increased risks of brain cancer and leukemia.
The true answer to the mammography dilemma is that we need a better screening tool. Breast MRI is too expensive and nonspecific and breast ultrasound is useful as a supplement to screening but not so much by itself. Coming soon to a breast center near you is 3D-Mammography, Breast Scintigraphy, 3D-automated Ultrasound, and Contrast-enhanced Ultrasound. All of these techniques as they are developed now have too many problems to stand by themselves but are promising in selective cases.
In the near future we will be tailoring screening for each patient based upon breast density, age, prior biopsies and overall risk. This will will have benefits of cost-reduction and less unnecessary biopsies but will still leave some women feeling vulnerable. The good news is that the mortality from breast cancer is continually improving with more effective, less destructive therapies being developed each year. Its a very promising time for breast cancer care as more patients are being cured than ever.