Data delays and other concerns
Unfortunately, clinical trials take time — to design, to conduct and to report results back to the scientific community which then uses that information to finesse screening guidelines.
“It also takes additional time to establish updated insurance coverage policies,” Lee said. “As a scientific community, beyond conducting new studies, we also need to be working to shorten the lag between closing knowledge gaps and improving clinical care.”
Approximately 43,000 people died of metastatic or advanced breast cancer in 2023; the majority of cases occur between ages 55 and 74 years of age.
Etzioni, who researches the risk vs. benefit of preventive cancer screening, expressed concern about the accuracy of mammography in the new subset of younger women, since women in their 40s tend to have denser breast tissue and dense breast tissue tends to “hide” breast cancer.
“Having dense breasts increases the biological risk — which has been confirmed by our research — but it also makes it harder to see the cancer,” she said, explaining that both dense tissue and breast cancer appear white on mammograms. It’s a bit like trying to spot a polar bear in a blizzard.
“If women in their 40s are to be screened, it’s critical to recognize that mammogram performance in this age group is not as good as in older women,” she said. “The Task Force recommendation is a guide. It’s important for women to know their breast density and to know what it means. Women with dense breasts may want to consider more frequent screening than every other year.”
The ACS states that 3D mammograms (also known as breast tomosynthesis) “might be particularly helpful” for those with dense breasts. ACS also recommends those at higher risk (based on inherited gene mutations, a strong family history of breast cancer or other factors), have an MRI along with a yearly mammogram.
Better surveillance for Black patients?
Black patients, who are 40% more likely to die from breast cancer than white women, may benefit the most from the new guidelines.
“Black women often have aggressive cancers at younger ages,” Lee said. “The new guidelines supporting eligible women, and especially Black women, to start screening at age 40 are important to better communicate the benefits of mammography for reducing breast cancer deaths.”
Breast cancer is the second leading cause of cancer mortality in U.S. women, but it’s the number one cause of death in Black and Hispanic women despite a steady decline in overall mortality rates over the past two decades.
Black women have a lower five-year survival rate, no matter the breast cancer subtype — or the stage — of the disease.
According to ACS Cancer Surveillance’s senior scientific director Rebecca Siegel, MPH, this points to discrepancies in care, rather than overly aggressive biological subtypes.
“We have been reporting this same disparity year after year for a decade,” she said in a recent news release. “The differences in death rates are not explained by Black women having more aggressive cancers. It is time for health systems to take a hard look at how they are caring differently for Black women.”
Etzioni said when it comes to screening guidelines, it’s all about finding the right balance.
“The Task Force does a very careful job of weighing benefits and harms and they truly try to recommend what they feel is the best balance,” she said.
“But what is not included in the calculation of benefit and harm is the benefit of having concurrent guidelines with other major national groups like the American Cancer Society versus the harms of having discordant guidelines.”