Mammogram rates decreased following controversial U.S. Preventative Services Task Force guidance that women under the age of 50 may not need routine screening, researchers found.
A Mayo Clinic team noted a 6% decline nationwide in mammograms for women in their 40s in the year after USPSTF revised its breast cancer screening guidance, a "small but significant decrease," researchers said.
The Mayo team took data from a database of 100 health plans to identify the number of screenings between January 2006 and December 2010, including nearly 8 million women aged 40 to 64.
Screening rates declined 5.7% among women aged 40-49 following the USPSTF’s recommendation, with nearly 54,000 mammograms skipped in 2010.
"For the 1st year after the guidelines changed, there was a small but significant decrease in the rate of mammography for women ages 40," Mayo Clinic researcher and study co-author Nilay Shah said in prepared remarks. "This is consistent with the context of the guidelines change. A modest effect is also in line with the public resistance to the guidelines change and the subsequent release of conflicting guidelines."
The USPSTF, an independent body funded and staffed by the U.S. Dept. of Health & Human Services, altered its mammogram recommendations in 2009 to advise that women under the age of 50 who aren’t at increased risk of developing breast cancer may not need routine screening.
The agency further recommended mammograms every 2 years for women aged 50 to 74, rather than the previously accepted yearly screenings, and cautioned against teaching women under the age of 50 to conduct breast self-examination.
The change created quite a backlash among some organizations, including the American Medical Assn. which earlier this month updated its mammogram screening recommendation to include all women starting at age 40.
The Mayo Clinic similarly recommends annual breast exams and regular mammograms beginning at age 40, according to a release.
The USPSTF’s 2009 decision overturned a 2002 report recommending mammograms in women aged 40 and older, but changed its mind in light of new data, including a randomized, controlled clinical trial and the Cancer Intervention & Surveillance Modeling Network’s modeling studies.
The agency issued the 2009 guidance after finding that the risk of breast cancer false positives were higher for women aged 40-49 while the risk of developing breast cancer was lower than that of women over the age of 50. USPSTF urged "the decision to start regular, biennial screening mammography before the age of 50 years should be an individual one and take patient context into account, including the patient’s values regarding specific benefits and harms."
"The USPSTF concludes that the current evidence is insufficient to assess the additional benefits and harms of clinical breast examination beyond screening mammography in women 40 years or older," according to the agency’s 2009 recommendation. "Although false-positive test results, over-diagnosis, and unnecessary earlier treatment are problems for all age groups, false-positive results are more common for women aged 40 to 49 years."