An independent medical expert panel that advises the US federal government on preventive and primary healthcare recommends against routine screening mammography in women aged 40 to 49 years and suggests instead that the decision to start regular screening before the age of 50 should be an individual one.

The recommendation, dated November 2009, comes from the US Preventive Services Task Force (USPSTF), a leading independent panel of private-sector experts in prevention and primary care, sponsored by the Agency for Healthcare Research and Quality (AHRQ) which is part of the US Department of Health and Human Services. The full statement with supporting documents is available on the AHRQ website.

The USPSTF recommends against routine screening mammography for women under the age of 50 and that for women younger than this the decision to have mammograms every two years should be an individual one that takes into account the patient’s individual context, including “the patient’s values regarding specific benefits and harms”.

In arriving at this recommendation, which updates their 2002 recommendation to screen routinely from age 40 upwards, the USPSTF reasoned that the “additional benefit gained by starting screening at age 40 years rather than at age 50 years is small, and that moderate harms from screening remain at any age”.

They stressed that the new recommendation is a grade “C” recommendation against routine screening at age 40 to 49 and that the Task Force “encourages individualized, informed decision making about when to start mammography screening”.

The main reason for raising the age band from 40 to 50 comes from a new systematic review that incorporates a randomized controlled trial that showed the risk reduction from screening is greater for women aged 50 to 59 than for those aged 40 to 49.

The USPSTF said that the trial estimated that the “number needed to invite for screening to extend one woman’s life as 1904 for women aged 40 to 49 years and 1339 for women aged 50 to 59 years”, and although the relative risk reduction is nearly the same for the two age groups, risk for breast cancer rises steeply from age 40 onwards, thus the absolute risk reduction from screening as shown by the number that would have to be invited, is greater for those aged 50 to 59 than for women aged 40 to 49.

In their new Screening for Breast Cancer statement the USPSTF also recommends:

  • Regular biennial screening mammography for women aged 50 to 74.
  • No teaching of breast self-examination (BSE).
  • There is not enough evidence to assess whether clinical breast examination (CBE) does more harm than good, beyond screening mammography in women 40 years or older.
  • Current evidence is not enough to assess whether digital mammography or magnetic resonance imaging (MRI) would be better or worse than film mammography.

Public Law Section 915 requires that the AHRQ convenes the USPSTF to “conduct scientific evidence reviews of a broad array of clinical preventive services, develop recommendations for the health care community, and provide ongoing administrative, research, technical, and dissemination support”.

According to the AHRQ, recommendations by the USPSTF are considered the “gold standard” for clinical preventive services.

However, many experts are not so happy about this new advice, and also the way it is worded.

By moving from a general statement about recommending routine screening for women aged 40 to 49 to one that says it should be decided on a case by case basis, there is a feeling that the USPSTF may encourage a view that screening mammography for women aged 40 to 49 is a waste of money.

According to a report in Reuters news agency, physicians like Dr Len Lichtenfeld, deputy chief medical officer of the American Cancer Society, are worried that insurers will seize on this recommendation as a way to control rising healthcare costs.

Another fear is that women will be so confused by the apparently conflicting statements in the recommendations that they will stop going for mammograms altogether, and “that would be the worst possible outcome”, said Lichtenfeld.

The American College of Radiology and the Society of Breast Imaging have also put out a detailed statement rejecting the USPSTF recommendation, pointing out that the goverment advisory panel has “no medical imaging representation”.

Their statement says that if the USPSTF policy is adopted, “two decades of decline in breast cancer mortality could be reversed and countless American women may die needlessly from breast cancer each year”.

Dr Carol H Lee, who chairs the American College of Radiology Breast Imaging Commission said that the USPSTF has ignored “valid scientific data” and their new recommendations seem to “reflect a conscious decision to ration care”.

“Mammography is not a perfect test, but it has unquestionably been shown to save lives — even in women aged 40-49,” said Lee.

“If Medicare and private insurers adopt these incredibly flawed USPSTF recommendations as a rationale for refusing women coverage of these life-saving exams, it could have deadly effects for American women,” she added.

Dr W Phil Evans, president of the Society of Breast Imaging (SBI) agreed:

“These recommendations are inconsistent with current science and apparently have been developed in an attempt to reduce costs.”

“At least 40 percent of the lives saved by mammographic screening are of women aged 40 – 49,” said Evans.

“Screening for Breast Cancer.”
Topic Page. November 2009.
US Preventive Services Task Force.
Agency for Healthcare Research and Quality, Rockville, MD.

Sources: USPSTF, SBI, Reuters.

Written by: Catharine Paddock, PhD