Task Force Issues Final Recommendations on Screening for Breast Cancer

Greatest benefit of mammography is in women ages 50 to 74

The U.S. Preventive Services Task Force has published a final recommendation statement on screening for breast cancer after reviewing the science on the benefits and harms of screening mammography, and after considering the input received from public and health care professionals on its 2015 draft recommendation. The task force examined the evidence on women who were not known to be at increased risk of breast cancer.

The recommendation statement consists of several recommendations that address different age groups and screening methods.

The task force confirmed that screening mammography is effective in reducing deaths due to breast cancer among women 40 to 74 years of age. The greatest benefit of screening mammography occurs in women ages 50 to 74 years, and these women get the best balance of benefits to harms when screening is done every two years.

“The task force, the American Cancer Society, and many others have all affirmed that mammography is an important tool to reduce the risk of dying from breast cancer, and that the benefits of mammography increase with age,” said task force chair Albert Siu, MD, MSPH. “We hope this growing convergence among distinct organizations gives women and their health care providers confidence in the science that supports mammography screening.”

For women in their 40s, the task force found that mammography screening every two years can also be effective and recommends that the decision to start screening should be an individual one, taking into account a woman’s health history, preferences, and how she values the potential benefits and harms of screening. Women in their 40s who have a mother, sister, or daughter with breast cancer may benefit more than average-risk women by beginning screening before age 50.

While the task force noted that screening mammography is effective in reducing deaths from breast cancer for women in their 40s, the likelihood of a benefit is less than that for older women, and the potential harms are proportionally greater. The most serious potential harm of mammography screening is unneeded treatment for a type of cancer that would not have become a threat to a woman’s health during her lifetime; the most common is a false-positive test result, which often leads to additional tests and procedures.

“Our findings support a range of choices available to women — from beginning regular mammograms in their 40s, to waiting until age 50 to begin screening, when the likelihood of benefit is greater,” says the task force’s vice chair, Kirsten Bibbins-Domingo, PhD, MD. “Women deserve to understand what the science says about mammography screening, so that they can make the best decision for themselves, in partnership with their doctor.”

For women 75 years of age and older, the task force found that there is limited evidence to support screening. None of the studies of breast cancer screening included women in this age group. Because of lack of evidence, the task force was unable to make a recommendation for or against screening these women and encourages additional research in this area.

Finally, the task force identified a number of areas where additional research is needed to better understand how screening might reduce breast cancer deaths. Specifically, the task force concluded that evidence is insufficient to determine the balance of benefits and harms in two additional areas: screening women with dense breasts, and the effectiveness of 3D mammography for the detection of breast cancer.

The task force is an independent, volunteer panel of experts in evidence-based medicine. It does not make recommendations for or against insurance coverage; coverage decisions are the responsibility of payers, regulators, and legislators. Legislators have recently extended a guarantee that most women with private insurance, beginning at age 40, will not have a copay for a screening mammogram.

The task force’s final recommendation and an accompanying editorial were published online in the Annals of Internal Medicine.

Source: USPSTF; January 12, 2016.