In Major Shift, American Cancer Society Says Begin Mammograms at 45

Women at Average Risk Should Begin Annual Screening at 45, And Require Only Biennial Screening After Age 55

Issue 26 Winter/Spring 2016

The American Cancer Society in October announced sweeping changes to its breast cancer screening guidelines, moving the age at which a woman at average risk for the disease should have her first annual mammogram from 40 to 45.

The ACS also says that, beginning at age 55, mammograms for women at average risk need only be done every two years, since this is adequate given the growth rate of most breast tumors in older women.

The group set no upper age limit to mammography screening. The Cancer Society also no longer recommends the clinical breast examination – where doctors or nurses feel the breast for lumps – in women without any symptoms of abnormality in the breast.

The new guidelines come after an exhaustive, two-year review of the current literature on breast cancer screening, according to the ACS, which last revised its guidelines in 2003. Since that time, the group had advocated for clinical breast exams and annual mammography beginning at age 40.

“These [new] recommendations are made with the intent of maximizing reductions in breast cancer mortality and years of life saved while being attentive to the need to minimize harms associated with screening,” Dr. Kevin Oeffinger, chair of the ACS’ breast cancer guideline panel, explained in a statement from the group.

Harms can include the danger of a false-positive result, which can cause a patient significant psychological trauma and, in many cases, unnecessary follow-up and treatments.

The new guidelines appear in the context of debate following guidelines on screening issued in 2009 by the United States Preventive Services Task Force (USPSTF), an influential government advisory panel.

Those guidelines moved the timing of first mammogram for a woman at average risk for breast cancer to age 50, with screening needed only every two years.

The American Cancer Society stressed that its new guidelines only apply to patients at average risk. Women who carry genes linked to an increased risk for breast cancer, or women with a family history of the disease, will need more careful monitoring, the ACS said.

Even for women at average risk for breast cancer, the group left the door open to individual choice. For example, the ACS states that women aged 40 to 44 “should have the opportunity to begin annual screening” should they decide to do so after talking with their doctor.

Elizabeth Fontham is chair of the ACS Guideline Development Group and founding Dean of the School of Public Health at LSU Health Sciences Center in New Orleans. Explaining the new guidelines, she said that, “though the evidence shows that there are some benefits from mammography screening starting at age 40, those benefits more clearly outweigh the harms from age 45 onward.”

“Still,” Fontham said, “some women will choose to begin screening between age 40 and 44 – both because they are concerned about their risk for breast cancer, either in general or because they are at higher risk, and are less concerned about the chances of experiencing a false positive finding. Those women should have the opportunity to start screening at 40 if they choose.”

As for postmenopausal women, the ACS panel believes that the risks of annual mammography may begin to outweigh benefits.

“The option to screen every two years for women at age 55 is based on the fact that post-menopausal breast cancers tend to develop more slowly,” explained Oeffinger, a family physician at Memorial Sloan Kettering Cancer Center in New York City. As well, several of the trials on breast cancer screening used a two-year interval and showed equivalent benefits to an annual mammogram.

Oeffinger said that after women pass menopause, they can consult with their doctor and decide whether to continue with annual mammography, or move to biennial screening.

What the new guidelines say:

  • All women should become familiar with the potential benefits, limitations, and harms associated with breast cancer screening.
  • Women with an average risk of breast cancer should undergo regular screening mammography starting at age 45 (strong recommendation*).
    • Women who are 45 to 54 years should be screened annually (qualified recommendation**).
    • Women who are 55 and older should transition to biennial screening or have the opportunity to continue screening annually (qualified recommendation).
    • Women should have the opportunity to begin annual screening between the ages of 40 and 44 (qualified recommendation).
  • Women should continue screening as long as their overall health is good and they have a life expectancy of 10 years or more (qualified recommendation).
  • The ACS does not recommend clinical breast examination for breast cancer screening among average-risk women at any age (qualified recommendation).

* A strong recommendation conveys the consensus that the benefits of adherence to that intervention outweigh the undesirable effects that may result from screening.

**Qualified recommendation indicates there is clear evidence of benefit of screening but less certainty about the balance of benefits and harms, or about patients’ values and preferences, which could lead to different decisions about screening.