Don’t Skip Your Mammogram After A False-Positive Result

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

Dense Breasts May be Leading Risk Factor For Breast Cancer

Women whose breasts are composed mainly of dense glandular tissue rather than fat may have higher odds of developing breast cancer, a recent study suggests.

Researchers examined data on more than 18,000 women with breast malignancies and 184,000 women the same age without breast cancer. They found breast density appeared to be the biggest indicator of cancer risk, even more than other common risk factors like family history or waiting until after age 30 to have babies.

“Women with dense breasts have a roughly 2-fold higher breast cancer risk relative to women with non-dense breasts,” said lead study author Dr. Natalie Engmann of the University of California, San Francisco.

This is a problem because 60 percent of younger women have dense breasts and so do 40 percent of older women who have gone through menopause – and because dense breasts make tumors harder to detect on mammograms, Engmann said.

“Our findings suggest that because breast density is a strong, common risk factor that can be modified, reducing the number of women with dense breasts may prevent a substantial proportion of breast cancer cases,” Engmann.

In the study, online February 2 in JAMA Oncology, researchers examined data on women with four categories of breast density: almost entirely fat, mostly fat with some dense tissue, moderately dense and predominantly dense. Then, they looked at several known breast cancer risk factors: women’s weight, family history of the disease, personal history of benign biopsy results, breast density and having a first baby after age 30.

About 39 percent of breast cancer cases before menopause and 26 percent of cases afterwards might be prevented if women in the two highest breast-density categories had less dense breast tissue, the study team calculated.

It’s unclear that women can do anything to reduce breast density, but it may make sense for them to consider screening alternatives to mammograms, said Dr. Christine Berg, a NCI researcher who wasn’t involved in the study.

“I think it makes more sense for a woman with dense breasts, particularly with other risk factors, to discuss with her doctor and the radiologist whether or not she would benefit from other types of screening such as MRI,” Berg said by email. “Breast tomosynthesis is an emerging technology which I think is better than standard mammography.”

Berg also recommended a calculator (here: developed by the Breast Cancer Surveillance Consortium for women to assess their individual risk.

Bottom line: For women with dense breasts, the addition of alternate screening such as 3D bilateral whole breast ultrasound or MRI can improve the early detection of breast cancer.

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.