Study Supports Breast Cancer Screening Every Two Years

More false positives with annual mammograms

October 24, 2011

According to a study of 170,000 women who had mammograms, a majority of women who get annual screenings have false-positive results.

A new study finds that women who have a mammogram every other year are less likely to get a suspicious result requiring additional testing as compared to women who have the breast cancer screening test every year.

The researchers found little risk in going two years between mammograms.

In 2009, a U.S. government expert committee, the U.S. Preventive Services Task Force, recommended breast cancer mammography every two years, starting at age 50. The previous standard was annual screening starting at age 40.

The change was controversial; many women and their doctors still follow the old recommendation.

This latest study examined the records of about 170,000 women who had mammograms. They found that a majority of women getting annual screenings had false-positive results.

"We found that more than half the women, after 10 years of annual screening, will be recalled for additional imaging," says Diana Miglioretti of the Group Health Research Institute in Seattle. "And it turns out they do not have cancer. And that seven percent of women will be recommended to have a biopsy that turns out not to show cancer."

Another finding in the study was that women who had mammograms every other year were slightly more likely to have a finding of cancer.