The emotional trauma of receiving a false-positive result from a mammogram may lead many women to delay or skip their next screening, a new study finds. A false-positive result means that an aberration on a mammogram looks like it might be cancer. But after tests — such as added imaging or biopsy — it turns out to be benign.
The finding, from a study of more than 261,000 Chicago-area women, highlights an unintended consequence of false positive results on screening mammography. The new study was led by Firas Dabbous, manager of patient-centered outcomes research at Advocate Lutheran General Hospital in Park Ridge, Ill. His team examined data on more than 741,000 screening mammograms conducted on nearly 262,000 women in the Chicago area. The study found that slightly more than 12 percent of the mammograms ended up yielding a false-positive result.
In cases where a mammogram was recommended every year, women who had an unfounded scare tended to delay their next test by an additional 13 months compared to a three- to six-month delay for women whose tests had come out negative.
That, in turn, can affect a woman’s chances of survival if breast cancer is subsequently diagnosed. Some women never showed up at all, but the researchers couldn’t determine whether they gave up on the breast cancer screening or simply had it done elsewhere.
“It’s a delicate balance,” chief author Firas Dabbous of Advocate Lutheran General Hospital in Park Ridge, Illinois, told Reuters Health. “We want to detect tumors when they are present but we don’t want to overburden women with a lot of false positives and a workup that is not needed.”
The study appeared online February 9th in the journal Cancer Epidemiology, Biomarkers and Prevention.
Debates over how often women should get mammograms often focus on whether false positives – which can cause women to experience anxiety as well as painful and expensive extra testing, including biopsies – represent a harm that outweighs the benefits of screening.
“Unfortunately, for women over age 50, just skipping a mammogram every other year would miss up to 30 percent of cancers,” said Dr. Stefanie Zalasin, a breast imaging specialist in New York who reviewed the new findings. She said that prior research has shown that “women who have had a false-positive mammogram are actually at greater risk for subsequently developing breast cancer. This is why it is extremely important that women continue annual screening mammography, even if they have had the experience of having a false-positive mammogram in the past.”
“Most U.S. studies have shown either greater adherence to screening recommendations after a false positive, or no difference, whereas studies done in Europe have shown screening rates somewhat lower than women who have true negative results,” Smith said.
Bottom line: Screening mammography has some limitations, but it’s increasing the survivability of the woman through early detection.
About the author: Raja P. Reddy, MD is a board certified diagnostic radiologist specializing in breast imaging. He is also a contributing editor for Women’s Imaging Specialists, a leading provider of outpatient women’s imaging services in the greater Atlanta, GA area