Guidelines for screening mammography traditionally recommended starting at age 40, but in October 2015 the American Cancer Society (ACS) decided to bump it up to age 45. New research that was presented at the Annual Meeting of the American Society of Breast Surgeons uncovered that risk assessment is critical to determine if women ages 40 to 44 require screening.

In response to ACS' guidelines, the American Society of Breast Surgeons (ASBrS) released similar guidelines with the additional recommendation that screening mammograms should begin at the age of 40 for women who have a lifetime risk of 15 percent or greater, or for those at risk of a breast cancer-related genetic mutation.

Researchers at the Massachusetts General Hospital (MGH) and Brigham and Women's Hospital in Boston decided to investigate how many women in their breast surgery practice between the ages of 40 to 44 were eligible for screening mammograms compared to women ages 45 and older.

"Critical to the development and interpretation of both of these new guidelines is formal risk assessment," Dr. Jennifer Plichta, breast surgery fellow at MGH and Brigham and Women's Hospital, said in a web briefing. "Furthermore, risk assessment is needed not only to determine who qualifies for mammography, but also who may require screening MRIs and/or genetic testing."

Plichta and her fellow researchers retrospectively reviewed a database of all new female patients who came to their breast surgery clinic and underwent a comprehensive risk assessment between March 2011 and October 2015. Patients with a history of breast cancer or a known breast cancer mutation were excluded.

Their review included nearly 7,000 women 40 and above who met their inclusion criteria, and of those, 13 percent were ages 40 to 44.

Risk calculations were used to determine the proportion of women ages 40 to 44 who had an increased risk of breast cancer and were thus eligible for screening mammography starting at age 40. The risk factors included those who met the ACS risk definition of 15 percent or greater lifetime risk, the ACS high-risk definition of 20 percent or greater and those at risk of having a genetic mutation.

The researchers found that patients between the ages 40 and 44 had a 46 percent lifetime risk of breast cancer of 15 percent or greater. In addition, one-fourth of the women were eligible for genetic testing.

"Since many patients fell within both groups, half of women ages 40 to 44 would have been eligible for screening mammography at the age of 40 under these new guidelines," concluded Plichta.

With regard to genetic testing, 25 percent of women ages 40 to 44 qualified, while only 17 percent of women 45 and older were eligible. Similar difference were observed with MR eligibility — 32 percent of those 40 to 44 qualified, but only 21 percent of those 45 and over were eligible.

"We believes that formal risk assessment is essential for women ages 40 to 44, in order to identify those who require screening mammography to start at the age of 40 and those who would qualify for screening MRIs and genetic testing," said Plichta.

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