Study Confirms Declining Mammography Rates in Breast Cancer Survivors

Rates of follow-up mammography among breast cancer survivors declined significantly during the last decade, particularly among younger women, an analysis of health claims data showed.

Rates of annual mammography decreased from 74.1% in 2004 to 67.1% in 2016, with all of the decline occurring from 2009 to 2016. Among breast cancer survivors ages 40 to 49, mammography rates decreased by 2.8% a year after 2009, double the rate of decline in women ages 50 to 64.

The rate of decline did not differ among women who had seen a breast cancer specialist or primary care physician within the previous year, reported Kathryn Lowry, MD, of the University of Washington in Seattle, and coauthors in the Journal of the National Comprehensive Cancer Network.

“I was surprised that we saw declines in mammography use among patients who were continuing to see their cancer specialists,” Lowry said in a statement. “It suggests we are seeing less frequent mammography participation even among those who are otherwise engaged in their cancer care. Our findings suggest we need to reinforce the importance of annual mammograms with our patients who have had breast cancer. We also need additional studies to better understand the barriers that are leading to fewer mammograms.”

For women with a history of breast cancer, surveillance mammography is a key component of follow-up care. In contrast to mammography recommendations for the general population, guidelines for breast cancer survivors consistently recommend annual surveillance mammograms, including guidelines from the American Society of Clinical Oncology/American Cancer Society, the National Comprehensive Cancer Network (NCCN), and the American College of Radiology.

Previous studies have shown that breast cancer survivors’ adherence to surveillance mammography declines as the time from breast cancer diagnosis increases, Lowry and coauthors noted. However, trends in surveillance mammography by calendar year have not been well documented.

A recent study from Michigan showed decreases in annual surveillance among women 40-49 during 2008-2009 and from 2012-2013. The decrease was attributed to a revision in the U.S. Preventive Services Task Force breast cancer screening guidelines, recommending biennial mammography for women with an average risk of breast cancer. Whether the decline was in fact related to the guideline change or representative of a national pattern was unclear, Lowry and colleagues noted.

Seeking Clarification

In an effort to clarify overall and temporal trends in surveillance mammography, investigators queried a nationwide commercial database and Medicare Advantage claims for the years 2004 to 2016. They linked socioeconomic data from the 2008 to 2012 American Community Survey. They identified 141,672 women ages 40 to 64 with a personal history of breast cancer. The cohort had a median age of 53 to 54, and over the course of the time period, about one fourth of the women were ages 40 to 49.

Adherence to annual surveillance mammography declined overall and in both younger and older age groups. However, younger women (40-49) consistently had lower rates of surveillance mammography throughout the study period. Overall, surveillance mammography rates decreased from 74.1% to 67.1%, but from 2009 to 2014 the rate decreased from 73.7% to 68.1%.

Among women ages 40 to 49, surveillance mammography declined from 70.4% to 57.1% from 2004 to 2016, including a decline from 68.7% in 2009. For women 50 to 64, the surveillance mammography rate remained stable from 2004 to 2009, and then declined from 74.1% to 68.6% in 2014 and to 67.9% in 2016. From 2009 to 2016, rates decreased by 2.8% annually in the younger women (P<0.001) and by 1.4% among women 50 to 64 (P<0.001).

Visits with specialists or primary care physicians did not influence the rate of decline. Women who reported visits with a surgeon or oncologist in the prior year had a 1.7% annual decline in surveillance mammography from 2009 to 2016 (P<0.001), and women who saw a primary care physician within the prior year had a 1.6% annual decrease in surveillance mammography (P<0.001).

Rates of surveillance mammography decreased irrespective of race, socioeconomic status, or geographic region, the authors reported.

Understanding Individual Patient Emotions

Although the study did not address potential reasons for the decline, the impact of individual patient characteristics and emotions cannot be underestimated, said Amy Sitapati, MD, of Moores Cancer Center at the University of California San Diego.

“While some people might feel excited and thrilled to go get their imaging, there is probably another group of people where encouragement might be quite helpful because they might have fear related to their experience and might not necessarily have the imaging done,” Sitapati, a breast cancer survivor and member of the NCCN guidelines panel for breast cancer, told MedPage Today.

“As a personal example, I went through all of the breast cancer treatment, and at some point, I had a follow-up mammogram and was told ‘Oh my God, your whole breast is full of cancer.’ I had a stereotactic biopsy and lots of tissue was removed, irradiated tissue, and it was uncomfortable and not the best experience. I was delighted that it turned out that everything was fine … but there’s emotion involved in all of that.”

Providing patients with a “nudge” or reminder about surveillance may be helpful in some cases, she added. Additionally, more studies should delve into patients’ personal reasons for not having surveillance mammography.

“Without asking cancer survivors about their reasons [for lack of adherence], we can’t get a balanced sense of what’s going on,” said Sitapati.