Benefits of routine screening may be greatest for women ages 50 to 74
Screening mammography is effective in reducing deaths due to breast cancer among women ages 40 to 74 years, per the final recommendations on the subject published in January by the U.S. Preventive Services Task Force. But 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.
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. 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 benefit is less than for older women and the potential harms 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 and may lead to anxiety and stress.
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 three areas:
- The benefits and harms of screening women age 75 and older.
- Adjunctive screening in women with dense breasts.
- The effectiveness of 3-D mammography for the detection of breast cancer.
The Task Force does not make recommendations for or against insurance coverage; coverage decisions are the responsibility of payers, regulators and legislators. Legislators recently extended a guarantee that women who have private insurance, beginning at age 40, will not have a co-pay for their screening mammogram.
The Task Force – an independent, volunteer panel of experts in evidence-based medicine – conducted a review of the science on the benefits and harms of screening mammography, and reviewed input received from the public and healthcare professionals on its 2015 draft recommendation. It examined the evidence on women who were not known to be at increased risk of breast cancer. The recommendation statement was published in Annals of Internal Medicine.