Research presented at a meeting of the Radiological Society of North America (RSNA) adds to existing evidence that women age 75 or older benefit from continued mammography screening, expanding the debate about whether the age recommendations for these screenings should change.
The retrospective review of medical records analyzed the outcomes of 763,256 screening appointments between 2007 and 2017. It found that although only 10 percent of the screening population were women 75 or older, this age group comprised 16.6 percent of the diagnoses for screening-detected cancers — a detection rate of 8.4 per 1,000, compared with 5.8 per 1,000 across all age groups. Most of the cancers reviewed for women 75 or older were early-stage tumors, but over half were grades 2 or 3. Furthermore, 82 percent of the cancers found were invasive.
“We believe there is value in screening this population,” says lead author Stamatia V. Destounis, MD, FACR, FSBI, FAIUM, radiologist and Partner at Elizabeth Wende Breast Care LLC in Rochester, New York. “Our beliefs are in line with the American College of Radiology and Society of Breast Imaging, which state that the age to stop screening should be based on each woman’s individual health status, rather than being an age-based determination.”
In 2009, the U.S. Preventive Services Task Force (USPSTF) released guidelines recommending against continued mammography screening past age 74 because of a lack of direct evidence that the benefits outweigh the harms.
While the USPSTF does not elaborate on the potential harms for older women, a primary drawback of mammography listed for women ages 40 to 74 is false-positive results, which can lead to invasive follow-up testing and have negative psychological effects, such as anxiety. According to Dr. Destounis, however, mammography actually performs better in older populations due to these women having less-dense breast tissue.
Judith A. Malmgren, PhD, Affiliate Assistant Professor of Epidemiology at the University of Washington and President of HealthStat Consulting Inc., concurs with these findings.
Malmgren co-authored a study published in 2014 in Radiology that tracked patients age 75 or older who had breast cancer. Using community-based institutional database records from 1990 to 2011, the study found that women in this age group whose breast cancer was detected through mammography experienced the same benefits as women in younger groups — earlier diagnosis, less treatment and a greater survival rate than patients whose breast cancer was self- or physician-detected.
“Deciding women shouldn’t be screened at a certain age is an arbitrary distinction, as the risk of breast cancer increases with age and the risk of having a biopsy that doesn’t reveal cancer goes down,” Malmgren says. “The benefits are just much stronger, in my opinion. No one wants to die of breast cancer. If you accept that premise, why would you think that women age 75-plus would want to die of breast cancer any more than younger women?”
Surgery may be another concern with this age group, but Dr. Destounis and her colleagues found that 98 percent of patients 75 or older were able to undergo surgery — similar to younger groups.
“Women ages 75 and over are vibrant and vital members of our society, often caregivers of their extended families and/or working outside their home. A small breast cancer can be easily treated with minimal surgery, allowing these women to continue living their lives.”
— Stamatia V. Destounis, MD, FACR, FSBI, FAIUM, radiologist and Partner at Elizabeth Wende Breast Care LLC
The Research Gap
The insufficient evidence cited by the USPSTF results from a lack of randomized, controlled trials, notes Charles H. Hennekens, MD, Sir Richard Doll Professor and Senior Academic Advisor to the Dean at Charles E. Schmidt College of Medicine at Florida Atlantic University. Dr. Hennekens says he understands the USPSTF’s stance.
In late 2015, he and his colleagues published a study in The American Journal of Medicine analyzing Medicare claims data from 1995 to 2009. His research found that women ages 75 to 84 who self-selected for annual mammograms had lower 10-year breast cancer mortality than women who had biennial or no/irregular mammograms.
Without a randomized, controlled trial, however, these results are simply hypothesis-generating data, according to Dr. Hennekens.
“There is very sparse data for the elderly, which is why we looked at claims data,” he says. “The most important thing we wanted to highlight was the evidentiary limitations of the data used for recommendations for this age group, which are based on self-reports and are much less reliable.”
Dr. Hennekens explains that clinical studies on the elderly are scant because the chance to improve life expectancy is lower than in younger populations. That can make it hard to justify the cost of this comprehensive research.
“The value of that data would have to be weighed versus the cost in light of the fact that we have an ever-expanding older population, composed mostly of women,” he says. “Politicians and health professionals have got to get together and decide where their priorities lie.”
According to U.S. Census Bureau projections, the number of American women of all ages is estimated to grow 7 percent from 2020 to 2030, whereas the population of women over 65 is expected to grow 30 percent.