Wednesday, November 18, 2009

Breast Cancer Screening with Mammograms at age 40? 50? Who is the USPSTF?

When the U.S. Preventive Services Task Force (USPSTF) updated their recommendations and were against routine mammography for women aged 40 to 49, it certainly got a lot of attention. These guidelines are far different than those advocated by the American Cancer Society (ACS) which recommends screening starting at age 40 with annual mammograms.

  • Who is the USPSTF?
  • What does their recommendations mean for women?
  • Why is there conflicting recommendations?
Who is the USPSTF?

The U.S. Preventive Services Task Force (USPSTF) is an independent committee of primary care and preventive physicians that periodically reviews the latest medical research and recommends tests and screening methods that have scientifically been shown to make a difference. As a result, its recommendations are the most conservative of any national organization.

The USPSTF’s recommendations are considered the “gold standard” for determining which clinical services are preventive. They review and look at various screening tests and preventive medications to determine whether there’s proof these interventions work and that the benefits they provide outweigh the potential harm. USPSTF indicates how strongly it recommends a particular method with a letter grade designation (A, B, C, D, and I). An A recommendation means that USPSTF strongly recommends that doctors provide a particular service to eligible patients. A B rating is simply a recommendation. A C means the task force recommends against routinely providing the service, but leaves the decision to the discretion of the individual doctor and patient. A D rating means the group recommends against providing for a particular intervention. An I recommendation indicates that there is not enough evidence to determine whether to recommend for or against a particular procedure.

The USPSTF recommendations tend to be the most conservative of any national organization, because they look for interventions that have proven benefits backed by research. Therefore, promising new technologies and tests that are yet unproven (and at times remain unproven or shown to be no better than existing tests) will not be recommended. As a result, the USPSTF’s guidelines may lag behind those of other organizations. But because they set such a high standard before recommending a particular treatment, insurers should cover the tests and procedures rated A and B.

From the November 2009 update on breast cancer screening update, the USPSTF recommended:

  • Against routine screening mammography in women aged 40 to 49 years. 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. Grade: C recommendation.
  • Recommended biennial screening mammography for women aged 50 to 74 years. Grade: B recommendation.
  • Current evidence is insufficient to assess the additional benefits and harms of screening mammography in women 75 years or older. Grade: I Statement.
  • Against teaching breast self-examination (BSE). Grade: D recommendation.
  • Current evidence is insufficient to assess the additional benefits and harms of clinical breast examination (CBE) beyond screening mammography in women 40 years or older. Grade: I Statement.
  • Insufficient evidence to assess the additional benefits and harms of either digital mammography or magnetic resonance imaging (MRI) instead of film mammography as screening modalities for breast cancer. Grade: I Statement.

What does this mean for women?

First, that there is some evidence that screening between ages 40 to 49 for breast cancer among women with average risk may not be as beneficial as we previously thought. There has been evidence from other countries, like Canada, which have suggested that. However, it is highly unlikely that the American Cancer Society (ACS), being an advocacy group for cancer awareness will change their stance. They said as much with the following:

The USPSTF says that screening 1,339 women in their 50s to save one life makes screening worthwhile in that age group. Yet USPSTF also says screening 1,904 women ages 40 to 49 in order to save one life is not worthwhile. The American Cancer Society feels that in both cases, the lifesaving benefits of screening outweigh any potential harms. Surveys of women show that they are aware of these limitations, and also place high value on detecting breast cancer early.

The American Cancer Society neglects to mention the potential number of extra women harmed with the extra screening between age 40 to 49. An additional 565 women need to be screened above and beyond the 1,339 women to save one life. Within this additional group, many women will have abnormal mammograms and require breast biopsies only to discover that the results were normal. The mammogram was a false-positive.

The USPSTF found in a study in the Annals of Internal Medicine, funded by the National Cancer Institute, that screening every other year achieved over 80 percent of the benefit of screening annually while cutting the false-positive result by nearly half. While every other year screening from age 50 to 69 years resulted in about a median 16.5% (range, 15% to 23%) decrease in breast cancer deaths compared to no screening, starting mammogram at age 40 decrease the death rate further by 3 percent, but increased the costs as more false-positive cases occurred. This article helped influence their recent decision.

Realistically for women, since ACS will not change their recommendation, is that mammograms will still be a covered benefit for any woman who desires to have a mammogram as early as age 40 and can be repeated annually.

What does this mean for you? If you are worried about breast cancer, consider getting screened starting at age 40, however, the benefit of screening may not be as good as we first thought. Certainly if there is a family history of breast cancer, you should discuss with your doctor whether mammography is enough or whether a breast MRI is needed.

Why are there conflicting information?

This won't be the first time USPSTF will have different recommendations than groups like ACS or other professional medical associations. Reasonable doctors and researchers can look at the same data and have different results. It speaks to the problem of screening for cancers and the tools that we currently have. The amount of precision that we would like as patients and doctors in identifying which group of individuals truly need a screening intervention and who does not have yet to be discovered. USPSTF and ACS disagree a bit on colon cancer screening as well. For example, when it comes to colon cancer screening USPSTF gives a grade A recommendation and suggests that:

Using fecal occult blood testing, sigmoidoscopy, or colonoscopy in adults, beginning at age 50 years and continuing until age 75 years. The risks and benefits of these screening methods may vary.

Yet, ACS also recommends virtual colonoscopy or stool DNA testing as reasonable alternatives even though there is no proof they save lives.

Stay tuned. Medical science continues to evolve and recommendations continue to change. The the mean time, exercise regularly, don't smoke, eat five servings of fruits and vegetables daily, and you might extend your life by an additional 14 years!

Your most crucial and trusted relationship is between you and your doctor. Questions? Speak up and ask. Don't be scared. Be informed.

1 comment:

Michael Kirsch, M.D. said...

Sebelius gave a very disappointing performance. She trashed the USPSTF, known as a thoughtful, deliberate and impartial organization. This was a huge step backward for health care reform and a win for politics and emotion. We missed a great opportunity to make real progress. See


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