Women age 50 to 74 with an average risk for breast cancer and no symptoms — including women with increased breast density — should undergo screening with mammography every other year, according to a new evidence-based guidance statement issued by The American College of Physicians (ACP) and published in Annals of Internal Medicine. The statement does not apply to women with prior abnormal screening results or to higher-risk populations, such as women with a genetic mutation or a personal history of breast cancer.

ACP
concluded that the potential harms of screening for breast cancer before age 50
years outweigh the benefits. These harms include receiving false-positive test
results, overdiagnosis, and undergoing unnecessary biopsy or surgery.

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The
guidance statement is based on a review of selected guidelines from around the
world for breast cancer screening and the evidence associated with them. All
national guidelines published in English between January 1, 2013 and November
15, 2017 in the National Guideline Clearinghouse or Guidelines International
Network library, as well as guidelines commonly used in clinical practice, were
included in the review.

Guidance Statement
1

In
average-risk women aged 40 to 49, clinicians should discuss whether to screen
for breast cancer with mammography before age 50. This discussion should
address the potential benefits and harms of screening, as well as the patient’s
preference.

Overdiagnosis
rates vary among age groups but are higher in women age 30 to 39, as are rates
for receiving a false-positive test result and unnecessary biopsy. The absolute
risk reduction in breast cancer mortality is lower in women age 40 to 49 than
in older women.

Guidance
Statement 2

In
average-risk women age 50 to 74, clinicians should offer screening for breast
cancer with biennial mammography.

The
ACP found little to no difference in breast cancer mortality for screening
every year vs screening every other year. Of note, women screened annually
received a recommendation for an unnecessary biopsy after a false-positive
result more often compared with women who were screened biennially (7.0% vs
4.8%).

Guidance
Statement 3

In
average-risk women age ≥75 or in women with a life expectancy ≤10 years,
clinicians should discontinue screening for breast cancer.

The ACP concluded that the decision to stop screening should incorporate the risk for cancer death, competing risk for other causes or death, the time lag between mammography and reduction in breast cancer mortality, the tradeoffs between benefits and harms, and the patient’s values and preferences. Most guidelines suggest discontinuing screening when, on the basis of advanced age or comorbid conditions, a women is unlikely to have a life expectancy long enough to benefit from screening. 

Guidance Statement
4

In
average-risk women of all ages, clinicians should not use clinical breast
examination (CBE) to screen for breast cancer.

No
guideline recommends screening with CBE if mammography is available, and
evidence is lacking for a mortality benefit of CBE alone or in combination with
mammography. CBE can result in overdiagnosis and false-positive results.

“Beginning at age 40, average-risk women without
symptoms should discuss with their physician the benefits, harms, and their
personal preferences of breast cancer screening with mammography before the age
of 50,” stated ACP President Ana María López, MD, in a press release from the
organization. “The evidence shows that the best balance of benefits and harms
for these women, which represents the great majority of women, is to undergo
breast cancer screening with mammography every other year between the ages of
50 and 74.”

References

  1. Qaseem A, Lin JS, Mustafa RA; for the Clinical Guidelines Committee of the American College of Physicians. Screening for breast cancer in average-risk women: a guidance statement from the American College of Physicians [published online April 8, 2019]. Ann Intern Med. doi:10.7326/M18-2147
  2. ACP issues guidance statement for breast cancer screening of average-risk women with no symptoms [news release]. Philadelphia, PA: American College of Physicians; April 9, 2019.

This article originally appeared on Clinical Advisor