Study Finds Missing Annual Mammogram Increases Risk of Death From Breast Cancer

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Regular mammography screening substantially reduces the risk of dying from breast cancer, according to a large study of over half a million women published by Stephen W. Duffy, MSc, and colleagues in the journal Radiology. Researchers said women who skipped even one scheduled mammography screening before a breast cancer diagnosis faced a significantly higher risk of dying from the cancer.

Stephen W. Duffy, MSc

Stephen W. Duffy, MSc

“This is the first time we’ve analyzed the mortality benefit of not just breast cancer screening, but regular breast cancer screening, using such a robust, comprehensive data set,” said Robert Smith, PhD, Senior Vice President of Cancer Screening for the American Cancer Society and a coauthor of the study.

Dr. Smith added, “This study comes at a critical time, as a staggering number of women have missed their regular mammogram over the past 12 months due to the period when screening services were suspended as a result of the pandemic, as well as enduring fears and barriers caused by the COVID-19 pandemic.”

Screening Patterns

In the new study, a multinational team of researchers took a more detailed look at screening attendance patterns to further refine mortality risk estimates. They analyzed data from almost 550,000 women eligible for mammography screening in nine Swedish counties between 1992 and 2016.

The women were divided into groups based on their participation in the two most recent scheduled screening exams prior to cancer diagnosis. Women who participated in both screening sessions prior to diagnosis were identified as serial participants, while those who did not attend either screening opportunity were categorized as serial nonparticipants.


Analysis showed that participation in the two most recent mammography screening appointments before a breast cancer diagnosis provided a higher protection against breast cancer death than participation in neither or only one examination.

The incidence of breast cancers proving fatal within 10 years of diagnosis was 50% lower for serial participants than for serial nonparticipants. Compared to women who attended only one of the two previous screens, women who attended both had 29% fewer breast cancer deaths.

“Regular participation in all scheduled screens confers the greatest reduction in your risk of dying from breast cancer,” said Prof. Duffy, Professor of Cancer Screening at Queen Mary University of London.

Prof. Duffy said the results add further evidence to support regular screening with mammography as a means for reducing breast cancer–related deaths. “While we suspected that regular participation would confer a reduction greater than that with irregular participation, I think it is fair to say that we were slightly surprised by the size of the effect,” he said.

“The message that women should take from this analysis is clear: regular screening tests can save your life,” said Dr. Smith.  “Regular mammography screening is an important part of a woman’s preventive health plan. And, if you’ve missed getting your mammogram during this pandemic, call your doctor to make up that appointment, and be conscientious going forward about getting regular mammograms.”

According to the Prevent Cancer Foundation, an estimated 35% of Americans missed routine cancer screening due to COVID-19–related fears and service disruptions early in the pandemic. In the United States in 2021, there will be an estimated 281,550 new cases of invasive breast cancer diagnosed in women and 43,600 deaths.

The study authors concluded, “Women participating in the last two breast cancer screening examinations prior to breast cancer diagnosis had the largest reduction in breast cancer death. Missing either one of the last two examinations conferred a significantly higher risk.”

Disclosure: For full disclosures of the study authors, visit

The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.