Interpreting the U.S. Preventive Services Task Force Breast Cancer Screening Recommendations for the General Population

Interpreting the U.S. Preventive Services Task Force Breast Cancer
Screening Recommendations for the General Populat

What are the new recommendations from the U.S. Preventive Services Task Force (USPSTF)? ion


The following recommendations for the general population appear in the November 17, 2009, issue of Annals of Internal Medicine (see www.annals.org):


The USPSTF recommends 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)
The USPSTF recommends biennial screening mammography for women aged 50 to 74 years. (grade B recommendation)
The USPSTF concludes that the current evidence is insufficient to assess the additional benefits and harms of screening mammography in women 75 years or older. (grade I statement)
The USPSTF recommends against teaching breast self-examination (BSE). (grade D recommendation)
The USPSTF concludes that the 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)

What were the previous (2002) USPSTF recommendations?


The USPSTF recommended screening mammography, with or without CBE, every 1-2 years for women aged 40 and older. (grade B recommendation)
The USPSTF concluded that the evidence was insufficient to recommend for or against routine CBE alone to screen for breast cancer. (grade I statement)
The USPSTF concluded that the evidence was insufficient to recommend for or against teaching or performing BSE. (grade I statement)
What do the USPSTF letter grades mean?

The USPSTF's recommendations are based on its assessment of net benefit—identified benefits minus identified harms. The USPSTF will only make a recommendation if it judges the available evidence to be of high enough quality that it can have high or moderate certainty as to the magnitude of the net benefit.

Interventions that are deemed to have substantial net benefit receive an A grade; interventions with moderate to substantial net benefit receive a B grade; interventions with small net benefit receive a C grade; interventions that have no net benefit (have harms that exceed the benefits) receive a D grade. If the evidence does not meet USPSTF standards, an "I statement" is issued.

Each letter grade is accompanied by a suggestion for practice. For A and B recommendations, the suggestion is to "offer/provide this service." For C recommendations, the suggestion is to "offer/provide this service only if other considerations support offering or providing the service in an individual patient." For D recommendations, the suggestion is to "discourage the use of this service." For I statements, the suggestion is to "read the clinical considerations section of USPSTF Recommendation Statement. If the service is offered, patients should understand the uncertainty about the balance of benefits and harms."

Grade C recommendations highlight the need for individualized decision making that considers the patient's own assessment of benefits and harms. The American College of Obstetricians and Gynecologists strongly supports shared decision making, and in the case of screening for breast cancer it is essential. Surveys have shown that women are more concerned about their risk of breast cancer than heart disease, which is more common. Many women, after weighing the benefits and risks for their own particular situation, will choose to have screening mammography.

What are the current recommendations from The American College of Obstetricians and Gynecologists?

The American College of Obstetricians and Gynecologists continues to recommend the following services:


Screening mammography every 1-2 years for women aged 40-49 years
Screening mammography every year for women aged 50 years or older.
BSE; BSE has the potential to detect palpable breast cancer and can be recommended.
CBE every year for women aged 19 or older
What is the College doing in response to the new recommendations?

The College, as a partner organization of the USPSTF, reviewed the draft recommendation statement and expressed concern regarding the implications of recommending against routine screening mammography for women in their 40s.

The College is continuing to evaluate in detail the new USPSTF recommendations and the new evidence considered by the USPSTF. The new recommendations and the evidence on which they were based will be reviewed by College committees that make recommendations on screening for breast cancer. Should the College update its guidelines in the future, Fellows would be alerted and such revised guidelines would be published in Obstetrics & Gynecology.

Why did the USPSTF recommend against routine mammography for women in their 40s?

The new USPSTF recommendations are based on a systematic evidence review by Heidi D. Nelson, MD, MPH, and colleagues and a modeling study by Jeanne S. Mandelblatt, MD, MPH, and colleagues that were published in the same issue of Annals of Internal Medicine as the recommendation statement. Based on these analyses, the 2009 USPSTF judged that although women in their 40s and women in their 50s benefit equally from routine screening mammography, women in their 40s experience greater harms from screening than do women in their 50s. Therefore, the USPSTF recommended routine screening for women aged 50-74 years but recommended against routine screening for women in their 40s.

The USPSTF's evaluation of the evidence found that the benefit to women in their 40s was virtually the same as the benefit to women in their 50s. The relative risk of breast cancer mortality for women randomly assigned to mammography screening was 0.85 in women aged 39-49 years and 0.86 in women aged 50-59.

Rather than benefit from screening, women without cancer who undergo mammography, additional imaging, and biopsies may incur harm. These outcomes were more common in women in their 40s (see Table). In addition, because the prevalence of breast cancer is higher in women in their 50s and because younger women are more likely to have dense breasts that may be difficult to assess on mammography, women in their 40s had more false-positive mammograms and underwent more additional imaging than women in their 50s.

abrir aquí para acceder al documento ACOG derivado del NGC AHRQ, del cual se reproduce un 50%:
Interpreting the U.S. Preventive Services Task Force Breast Cancer Screening Recommendations for the General Population