Amer Cancer Society Breast Screening Guidelines Create Confusion
by Dr. C.H. Weaver M.D. 9/2020
The American Cancer Society (ACS) has changed its recommendations for breast cancer screening in 2018. The ACS now recommends:
- Annual mammogram for women at average risk beginning at age 45 and continuing for ten years;
- After age 55, mammography screening every other year for all women with a life expectancy of at least 10 years;
- Clinical breast exams (CBE) no longer recommended as a screening tool.
The most significant, and potentially controversial, change in the ACS guidelines is the recommendation that women at average risk wait until they reach age 45 for their first breast cancer screening, as opposed to getting a baseline mammogram at age 40.
Other respected medical organizations, such as the American Congress of Obstetricians and Gynecologists, the National Comprehensive Cancer Network, and the American Medical Association continue to recommend annual screening beginning at age 40, while the U.S. Preventive Services Task Force (USPSTF) has recommended increasing the age to 50. In light of the ACS position, the National Consortium of Breast Centers has just reaffirmed that mammography screening should begin at the age of 40 for women of average risk.
Why would the ACS increase the age to 45 years for routine breast screening to begin? The organization’s stated concern is over diagnosis from early screening and the potential for increased morbidity and anxiety among women who will ultimately be found not to have invasive breast cancer.
Although not specifically stated, many suspect increased societal costs attributed to screening mammography have contributed to the ACS recommendations. This raises concerns as to whether the ACS is advocating for individual cancer patients or is more closely aligned with government and policy maker’s objectives. The major impact from the ACS recommendations are that they will influence insurance coverage decisions resulting in women under 45 having to pay for their mammograms instead of them being covered by their insurance.
Breast cancer remains the number one malignant cause of death in women between the ages of 35 and 60, and is a leading cause of death of women in their thirties, forties and fifties, overall. In fact a figure in the actual ACS analysis shows that women diagnosed before age 45 account for over 25 percent of person-years of life lost due to breast cancer.
In their analysis, the ACS authors note that women between ages 40 and 49 are more likely to have a false-positive mammogram than older women. While this is an important consideration, if the problem is that premenopausal women are so vulnerable to erroneous screening, perhaps the focus of reform should be on improved screening technology instead of reducing screening. Potential improvements could include same-day ultrasound and a requirement that all images be interpreted by breast imaging sub-specialists. Moreover, the establishment of a “baseline” mammogram at 40 might help reduce false positive mammograms in later years.
How the ACS concludes that 45 years is the threshold when the risk-benefit of screening mammograms suddenly tips to justify screening mammograms from never to every single year seems completely arbitrary. There’s every reason to begin breast cancer screening at age 40 years: both screening methods and pathology tools have improved, so there should be less for women to be anxious about than in previous years. Concern about fear or anxiety should not form the basis of any screening recommendations. The ACS should be encouraging women to take charge of their health and be empowered and engaged in the process.
The ACS recommendation to cease screening mammograms for older women who are unwell and unlikely to live for another decade does make sense, as does the third recommendation to cease clinical breast examination as a screening tool, which is consistent with the results of clinical trials that don’t support the utility of doctors or nurses examining patients’ breasts for cancerous lumps.
The United Kingdom Chimes In
When should women begin getting mammograms? Guidance varies around the world and is based on an individual’s family history or other high-risk identifiers. A recent study out of the United Kingdom suggests that starting breast cancer screenings earlier could have a large impact on the mortality rate of the disease. Currently the UK’s breast cancer screening program advises mammograms every 3 years for women aged 50 to 70
A recent study in The Lancet Oncology detailed a UK clinical trial that began yearly breast cancer screenings in women from around the age of 40 years and older. Across 23 breast screening units in England, Wales, and Scotland, 160,921 women aged 39 to 41 were recruited for the study between 1990 and 1997. One-third of the participants (53,883) were randomly assigned to the intervention group, which involved receiving yearly mammographic screenings up to and including the age of 48. The other two-thirds of women (106,953) were assigned to standard screening beginning at age 50.
After 10 years of follow up 83 women who began screening at 40 had died of breast cancer compared with 219 women who began screening at 50. The researchers concluded that earlier and more frequent mammographic screenings (yearly screenings beginning around age 40 to 41 as opposed to every 3 years beginning at age 50) was associated with a reduction in breast cancer mortality.
This study is not the only recommendation for a lower age for breast screenings. The American Cancer Society recommends that women should get mammograms every year from the ages of 45 to 54, and that they should be allowed the choice to begin these screenings from ages 40 to 44.² This, in their estimation, is more effective for early detection of breast cancer.
Ultimately, women should review the new guidelines with their physician. The ACS failed to acknowledge that most women at age 40 are at sufficient risk for developing breast cancer that it’s worth getting screened. They should be advised to do so, and not be afraid.
- Duffy S, Vulkan D, Cuckle H, et al. [Effect of mammographic screening from age 40 years on breast cancer mortality (UK Age trial): final results of a randomised, controlled trial.](https://www.thelancet.com/journals/lanonc/article/PIIS1470-2045(20%2930398-3/fulltext) The Lancet Oncology. 2020;21(9):1165-1172. doi:10.1016/s1470-2045(20)30398-3
- American Cancer Society Guidelines for the Early Detection of Cancer.org. Revised July 30, 2020. Accessed September 10, 2020.