The study found that women with a family history of breast cancer may not need an early mammogram

A new study, published in the American Cancer Society journal Cancer, reconsiders guidelines
for when to start a mammogram if a woman's mother, sister or daughter is diagnosed with breast cancer.

Women with a first-degree relative diagnosed with breast cancer are often advised to be screened 10 years earlier than the age of diagnosis of the relative, and these women are at average
risk in other areas.
However, there is little evidence to support this long-standing recommendation
.

Diana Miglioretti, a researcher at UC Davis Comprehensive Cancer Center, was involved in the study
along with Danielle Durham of the Department of Radiology at the University of North Carolina at Chapel Hill and five other researchers.
They analyzed data from the Breast Cancer Surveillance Consortium on mammogram screenings performed between 1996 and 2016 to assess when women with a family history of breast cancer should start screening
.

More than 300,000 women participated in the national study
.
The researchers compared the 5-year cumulative incidence of breast cancer in women with and without a family history of first-degree breast cancer, by age at diagnosis and age at screening
.

The study concluded that women whose relatives were diagnosed before age 45 or 45 might consider starting screening 5-8 years before the age of diagnosis of relatives, rather than 10 years
earlier, in consultation with their doctor.
This puts them at risk equal to the average risk for women in their 50s, which is the most recommended age
to start a mammogram.
”

BRCA mutation carriers may benefit from starting screening
early.
Women aged 30-39 who have more than one first-degree relative diagnosed with breast cancer may consider genetic counseling
.

Increasing the age at which to start screening can reduce the potential harms
of starting breast cancer screening early.
This includes increased radiation exposure and false-positive results that require women to return to the clinic for diagnostic imaging and possibly invasive surgery, but do not result in a breast cancer diagnosis
.
The earlier a woman gets a mammogram, the more screening they will receive in their lifetime – which increases the chances of
suffering these injuries.

"Mammography may also not work as well in younger women because their breasts are more likely to be dense, which makes it harder to spot cancer on images, leading to more false positives
," Miglioretti said.

Other authors of the study include Linn A.
Abraham of the Kaiser Institute for Permanent Health Care in Washington; Megan C.
Roberts, Escherman School of Pharmacy, University of North Carolina; Carly P.
Khan, Institute for Patient-Centered Outcomes; Robert A.
Smith, American Cancer Society and Karla Kerlikowske, UCSF Health
.
Miglioretti is an affiliated fellow
at the Center for Health Policy and Research at the University of California, Davis, and the Kaiser Center for Permanent Washington Health Research.

The research was funded
by the Cancer Prevention Fellowship Program, the Department of Cancer Prevention, and the National Cancer Institute (NCI) of the National Institutes of Health.
Data collection by the Breast Cancer Surveillance Alliance is funded by the NCI (grant numbers P01CA154292, U54CA163303 and PCS-1504-30370).