Why Do Women Go Against National Guidelines for Breast Cancer Screenings?

Despite many health recommendations, a new study shows that women in their 40s continue to undergo routine breast cancer screenings despite national guidelines recommending otherwise.

In 2009, the U.S. Preventive Services Task Force (USPSTF) sifted through the evidence and recommended that while women ages 50-74 should continue to undergo mammograms every two years, those between the ages of 40 and 49 without a family history of breast cancer should discuss the risks and benefits of routine screening mammography with their physicians to make individual decisions.

Lauren D. Block, M.D., M.P.H., a clinical fellow in the Division of General Internal Medicine at the Johns Hopkins University School of Medicine, also believes that colleagues expected to find fewer women in their 40s getting routine mammograms. However, this was not the case. Instead, they found no impact on mammography rates among younger women, according to the study.

"Patients - and likely their providers - appear hesitant to change their behavior, even in light of evidence that routine screening in younger women carries substantial risk of false positives and unnecessary further imaging and biopsies," said Block, the leader of a study. "Women have been bombarded with the message 'mammograms save lives,' so they want them no matter what."

This research shows that mammography's impact on younger women is mixed at best. For example, routine screening increases rates of detecting cancer in young women, but reduces mortality risk by a very small percentage. Researchers believe it is more likely that the studies show the results in over-diagnosis and unnecessary treatment, including biopsies, lumpectomies and mastectomies, with weeks of radiation and potentially toxic drugs. False positives result in avoidable procedures and psychological trauma. Many of the cancers detected will probably never be dangerous, but are aggressively treated.

Block and her colleagues analyzed mammogram use data from Behavioral Risk Factor Surveillance System surveys administered in 2006, 2008 and 2010 by state health departments nationwide. Data from 484,296 women ages 40 to 74 were collected. Among women in their 40s, 53 percent reported having a mammogram in the past year in 2006 and 2008, compared with 65 percent of women ages 50 to 74. In 2010, after the new recommendations had been in effect, 52 percent of younger women and 62 percent of older women reported having a mammogram.

Among older women, screening mammograms are recommended as breast cancer, like most cancers is a disease of aging and older women are often at a greater risk.

The original USPSTF guideline change recommended more forcefully against routine screening for women in their 40s. However, the American Cancer Society continues to recommend yearly mammography for women starting at age 40.

Moreover, Block said, insurance companies continue to pay for routine mammograms for women in their 40s, and is therefore a likely reason why they remain high.

The USPSTF recommendations also say there is no benefit to screening women at normal risk of breast cancer over the age of 75.

"Breast cancer gets so much attention in the media and in society in general, despite cardiovascular disease being by far the number one killer in women. Everyone wants to feel as though they are preventing breast cancer," Block said. "You hear one anecdotal story about someone in their 40s who found cancer during a mammogram and did really well with treatment and that's enough to fly in the face of any other facts that are out there. Women want the test."

The results for the study can be found online in the Journal of General Internal Medicine.