Over decade of annual screening, half of women have false-positive mammogram

About half of women who undergo a mammogram will have a false-positive result sometime over 10 years, according to a new study. Photo by Rhoda Baer/Wikimedia Commons
About half of women who undergo a mammogram will have a false-positive result sometime over 10 years, according to a new study. Photo by Rhoda Baer/Wikimedia Commons

March 25 (UPI) -- As many as half of women who undergo breast-cancer screenings experience a false-positive mammogram result over 10 years of annual evaluations, a study published Friday by JAMA Network Open found.

The study looked at results from digital breast tomosynthesis, or 3D mammography, as well as two-dimensional mammography.


The risk for false-positive results after 10 years of screening was considerably lower for women who have a 3D mammogram every other year, the researchers said.

In addition, repeated breast cancer screening with 3D mammography only reduced the likelihood of having a false-positive result slightly when compared with standard digital two-dimensional mammography, they said.

RELATED Study: AI for accurate mammogram readings not yet ready for prime time

Women with non-dense breasts also were less likely to have a false-positive result on 3D mammography, according to the researchers.

"Findings from our study highlight the importance of patient-provider discussions around personalized health," study co-author Michael Bissell said in a press release.


"It is important to consider a patient's preferences and risk factors when deciding on screening interval and modality," said Bissell, an epidemiologist at the University of California-Davis.

RELATED Study: Risk for cancer greater in older women with high breast tissue density

A false-positive occurs when a mammogram is flagged as abnormal, even when there is no cancer in the breast, according to

Nearly one in five women who undergo screening are called back for reevaluation due to false-positive results, the University of Rochester Medical Center in New York estimates.

Breast cancer is the second-leading cause of cancer-related death among women in the United States, and early detection with mammography lowers the risk for advanced breast cancer and death from this disease, according to the American Cancer Society.

RELATED Skipping mammograms raises odds for breast cancer death in women

However, a false-positive result often leads to more testing for women who receive them but no diagnosis of breast cancer, Bissell and his colleagues said.

When abnormalities are found on a mammogram, women are usually recalled for additional imaging and follow-up tests, the researchers said.

If found to be cancer-free at the end of this diagnostic reevaluation -- and for one year after her recall -- a woman is considered to have received a false-positive result, they said.

Although around 12% of women screened using 2D mammography are recalled for more tests, only 4% of those recalls, or fewer than 1%, result in a cancer diagnosis, according to the researchers.


For this study, Bissell and his colleagues analyzed data collected by the Breast Cancer Screening Consortium, which records mammography trends nationally, for 3 million screenings performed on 903,495 women ages 40 to 79 years.

The screenings were performed between 2005 and 2018 at 126 facilities across the country, the researchers said.

The researchers evaluated the mammography technology used, the time between screenings, patient age and breast density, they said.

The probability of receiving at least one false-positive result over a 10-year period was slightly lower with 3D than 2D digital mammography, according to the researchers.

With 3D mammography, about 50% of women experience at least one false-positive result compared with 56% of those screened with 2D digital mammograms, the data showed.

The decrease in false-positive results s with 3D versus 2D mammography was greatest for women with non-dense breasts and those who had annual screenings, the researchers said.

Women who underwent 3D mammography every other year were about 40% less likely to have a false-positive result, they said.

Regardless of the type of screening, false-positive results were substantially lower for older than younger age groups and women with entirely fatty versus extremely dense breasts, according to the researchers.

"Despite the important benefit of screening mammography in reducing breast cancer mortality, it can lead to extra imaging and biopsy procedures," co-author Diana Miglioretti said in the press release.


This can cause unnecessary "financial ... costs, and patient anxiety," said Miglioretti, professor and division chief of biostatistics at the UC-Davis.

Latest Headlines


Follow Us