The International Agency for Research on Cancer (IARC) concluded that there was
sufficient evidence that mammography reduces breast cancer mortality in women
ages 50 to 69 and 70 to74, but limited evidence for women ages 40 to 44 and better
but still limited evidence for women 45 to 49 years of age.
Two letters to the editor of the New England Journal of Medicine commenting on
the IARC working group report disagreed with their findings. One author pointed
out that in European countries, reductions in breast cancer mortality were greater
among women not screened than among those who were screened. He concluded
that screening resulted in overdiagnosis, the detection of cancers that will not cause
death or symptoms.The other author disputed the IARC finding that mammography
would decrease breast cancer mortality among women in the 70 to 74 age
It is not surprising that when a Swiss Medical Board’s report on mammography was
made public in 2014, its recommendation to limit mammography programs was
highly controversial1 It acknowledged that systematic mammography screening
might prevent about one death attributed to breast cancer for every 1000 women
screened, even though there was no evidence to suggest that overall mortality was
affected. At the same time, it emphasized the harm — in particular, false-positive
test results and the risk of overdiagnosis. The board, therefore, recommended that
no new systematic mammography screening programs be introduced and that a time
limit be placed on existing programs.
Additional evidence in favor of mammography reducing the risk of fatal breast cancer
comes from a large Swedish study published in the journal Cancer in 2020.
In Sweden, the mammography screening recommendation is every 18 months beginning
to at age 40 and every 24 months for those aged 55 to 69. The study of
549,091 women found a 41% lower incidence of breast cancer that was fatal within
10 years in women participating in screening compared with women not screened
and a 25% reduction in the incidence of advanced disease. The study could not rule
out the possibility that women who underwent screening had healthier behaviors
that could account for the reductions in breast disease that were observed.
A 2017 study among Dutch women published in the British Medical Journal found little
evidence that mammography screening reduced advanced breast cancer or mortality.
However, several experts concluded that the evidence from the Swedish study
indicates that screening saves lives. A study modeled the cost of the common practice of annual mammography compared to USPSTF guidelines of less frequent screening. The estimated cost of
annual screening of 85% of the population of women would be $10.1 billion compared
to $3.5 billion for screening according to the USPSTF’s recommendations,
guidelines that the authors of the study consider to be based on scientific evidence
and most likely to maximize patient benefit and minimize harm. The cost savings
would be enough to double the annual budget of the National Cancer Institute.
According to the ACS, research does not show a clear benefit of physical breast
exams done by either a health professional or by an individual, so regular clinical
breast exams and breast self-exams are no longer recommended. Still, the ACS suggests
that women should be familiar with how their breasts normally look and feel
and report any changes to a health care provider right away.
For more information on breast cancer screening consult the ACS document Breast
Cancer: Early Detection (http://www.cancer.org/cancer/breastcancer/moreinformation/
breastcancerearlydetection/breast-cancer-early-detection-toc); the (2016)
Final Recommendation Statement, Breast Cancer: Screening of the U. S. Preventative
Services Task Force (http://www.uspreventiveservicestaskforce.org/Page/Document/
RecommendationStatementFinal/breast-cancer-screening1); and the Journal
of the American Medical Association Patient Page (http://jama.jamanetwork.com/
This blog presents opinions and ideas and is intended to provide helpful general information. I am not engaged in rendering advice or services to the individual reader. The ideas, procedures and suggestions in that are presented are not in any way a substitute for the advice and care of the reader’s own physician or other medical professional based on the reader’s own individual conditions, symptoms or concerns. If the reader needs personal medical, health, dietary, exercise or other assistance or advice the reader should consult a physician and/or other qualified health professionals. The author specifically disclaims all responsibility for any injury, damage or loss that the reader may incur as a direct or indirect consequence of following any directions or suggestions given in this blog or participating in any programs described in this blog or in the book, The Building Blocks of Health––How to Optimize Your Health with a Lifestyle Checklist (available in print or downloaded at Amazon, Apple, Barnes and Noble and elsewhere). Copyright 2021 by J. Joseph Speidel.