Debate On Dense Breasts And Mammograms Rekindled
August 22, 2012

Does Breast Density Really Affect Mammogram Results?

Connie K. Ho for — Your Universe Online

Based on a new study, the discussion on whether the density of breasts can affect the image resolution of mammograms has been rekindled.

To begin, past studies have stated that women with dense breasts have a greater risk of developing breast cancer than women who have breasts with more fatty tissue. Proponents of these studies have noted that it is difficult for mammograms to catch a developing tumor due to dense tissue and possible cancerous spots that are not noticed on the X-ray. However, a recent project by the National Cancer Institute (NCI) with 9,000 breast cancer patients found that women who have dense breasts do not have a greater risk to die than patients who have breasts that are not dense.

"It's definitely reassuring," commented NCI lead researcher Dr. Gretchen Gierach, author of a report in the Journal of the National Cancer Institute, in an article by the Associated Press (AP).

With the new study, researchers believe that though tumors could possibly be found later in a dense breast, the tumors could be treated once diagnosed.

"That risk factor doesn't affect her ability to respond to treatment, and treatment is good," co-author Dr. Karla Kerlikowske, researcher who studies breast density at the University of California, San Francisco, told the AP.

The project highlighted how the issue of dense breasts affecting mammograms was only found in certain populations.

"It's a bit of a surprise," noted Barbara Monsees, chairwoman of the American College of Radiology's breast imaging commission who is unaffiliated with the study, in a USA Today article. "It shows we have a lot to learn about dense breast tissue and its implications for screening, diagnosis and treatment."

The study showed that an increased risk was only certain in obese women or women who had large tumors. The researchers propose that the significant amount of hormones related to obesity could explain the link between obesity and tumors. Researchers also believe that more studies need to be done on the topic to better understand the affect that breast density as in the development of cancer.

"There's a large proportion of women who have dense breasts, but most of those people don't get breast cancer,” explained Kerlikowske in the AP article.

According to the AP, dense tissue is milk-producing and connective tissue that shows up as white; white is the same color of possible cancerous spots and allows the spots to blend in. Density is more common in younger women and thought to reduce with age; half of women under the age of 50 have dense breasts, as compared to a third of women older than 50 years of age who are thought to have dense breasts. Over the last three years, state laws have mandated that mammogram providers alert women regarding breast density; these laws have appeared in places like Connecticut, New York, Texas, and Virginia.

As well, one concern for medical experts is the difficulty of measuring breast density as it can depend on the perspective of individual radiologists and on a particular mammogram.

"We're making policy in a gray area where the experts and doctors don't know what it means," explained Dr. Otis Bralwey of the American Cancer Society in the AP article.

Other factors can  impact a women´s risk of developing breast cancer, including past family history.

"What we want to do is save lives from breast cancer," Monsees told USA Today. "Whether we can do that with additional screenings is unknown."