Much Unknown About Role of Breast Density in Cancer

August 22, 2012 — Women increasingly are aware that breast density affects breast cancer risk and mammogram results, but it is not always clear how they should make use of that information, the AP/Sacramento Bee reports.

Women with very dense breast tissue have a higher chance of developing breast cancer than women with fattier breast tissue. Additionally, it can be harder for mammograms to detect possible tumors in dense tissue.

For women with dense breasts, ultrasounds or MRIs might be a better option for screening, but those tests can be more expensive and can lead to more false alarms, the AP/Bee reports. Although some states now require health care providers to inform women if a mammogram indicates they have dense breast tissue, critics of such legislation have noted that women might not know what to do once they are informed.

One concern among doctors and advocates is that there is no standard way to measure breast density. Radiologists divide density into four categories: women with almost completely fatty breasts, those with scattered dense areas, women with widespread density and those with extremely dense breast tissue. The American College of Radiology released a brochure this month to help women understand breast density and the debate over testing.

Until recently, another unknown was whether breast density affects breast cancer survival. A study released on Monday by the National Cancer Institute concluded that women with denser breasts were not more likely to die or less responsive to treatment than other women. Although tumors in dense breasts might be found later, they do not appear to be more aggressive or harder to treat than tumors in less-dense breasts, according to study co-author Karla Kerlikowske of the University of California-San Francisco (Neegaard, AP/Sacramento Bee, 8/20).