A survey of women in their 40s suggests that around one in ten of them would choose to delay screening mammography when given a decision aid that informs them about the benefits and potential harms of breast cancer screening.
“The U.S. Preventive Services Task Force (USPSTF) has written forcefully that people have a right to be informed about the potential benefit and harm of all preventive care,” said study first author Laura Scherer, PhD, from the Adult and Child Center for Outcomes Research and Delivery Science at the University of Colorado School of Medicine. “For mammograms in particular there is a balance of benefits and drawbacks. Some people don’t find the drawbacks to be concerning at all, but some people do find them concerning.”
The decision aid included information on the U.S. Preventive Services Task Force (USPSTF) and American Cancer Society screening recommendations as of 2022, screening benefits, false-positive screening results, overdiagnosis, a personal risk estimate, and decision-making vignettes that comprised three hypothetical stories about people at high, average, and low breast cancer risk making decisions about when to begin having mammography.
It was given to a nationally representative sample of 495 women aged 39 to 49 years without a history of breast cancer or a known BRCA1/2 gene mutation. The participants completed two 20-minute surveys, which asked them to select the statement that best reflected the age at which they would like to have mammography from the following options: “Start having regular mammograms at my current age,” “Wait until I’m older but before age 50 to start having regular mammograms,” “Wait until I am 50 to start having regular mammograms,” or “Not planning to have a mammogram in the future at any age.” For participants who had undergone breast cancer screening in the past, “start having regular mammograms” was replaced with “continue having regular mammograms.”
Before viewing the decision aid, 27.0% of participants preferred to delay screening rather than have a mammogram at their current age. This proportion increased to 38.5% after they had read the decision aid. Of these, 8.5% said they preferred to wait until age 50 years to have regular mammography before seeing the decision aid compared with 18.0% after.
This finding is particularly relevant given that the USPSTF recently changed its recommendation for mammography screening from informed decision making to biennial screening for women aged 40 to 49 years.
Although there there was an increase in the number of women who said they preferred to wait to have mammograms, the number of women who never wanted to have mammograms did not change significantly. Before the decision aid 5.4% said they never wanted screening compared with 4.3% after.
“There was no evidence that informing people deterred their interest in screening altogether,” said Scherer.
Participants who preferred to delay screening had lower breast cancer risk scores than those who preferred not to delay. They were also younger and more concerned about overdiagnosis and false-positive results. Some said they intended to do breast self-examinations instead of screening, which is not recommended. A small number expressed beliefs that were conspiracy-minded or misinformed, such as believing that squeezing the breast during mammography causes cancer or that overdiagnosis is a plot to get money, the researchers report in the Annals of Internal Medicine.
In contrast, those preferring to be screened at their current age often prioritized early detection, were following a preexisting plan, or wanted information about their health. Many mentioned a family history of cancer as well as having dense breasts.
“These data suggest that many of these women were similarly considering the evidence and deciding that, for them, the benefits of screening outweighed the harms,” Scherer et. al remark.
The surveys also assessed whether the health information given in the decision aid was surprising and differed from past messages people have received. This revealed that 37.4% of participants felt that the information about overdiagnosis was surprising, compared with 27.2% and 22.9% for information about false-positive results and screening benefits, respectively.
Scherer and co-investigators conclude that the study “reinforces that most women want to receive breast cancer screening in their 40s.”
However, “some people, especially those at lower risk, may want to wait to screen to maximize their chance of benefit and minimize the chance of harm,” said Scherer. “The fact that people’s perspectives on the evidence differs indicates that they should be informed.”
She adds that, importantly, the study shows “that we need to reduce barriers to receiving desired preventive care while also respecting people’s preferences and their autonomy to make an informed choice.”
