News | April 21, 2010

Decreasing Breast Density Lowers Cancer Risk

April 21, 2010 - A decrease in breast density, or the proportion of fibroglandular tissue depicted on the mammogram image, over a number of years is associated with decreased risk of breast cancer, reported researchers from the Mayo Clinic campus in Minnesota at the American Association for Cancer Research (AACR) 101st Annual Meeting 2010.

Lead investigator, Celine Vachon, Ph.D., an associate professor of epidemiology, presented the results. Vachon and her team of researchers found a 28 percent reduced risk of developing breast cancer in women whose breasts decreased in density. They looked at two different mammograms taken an average of six years apart, compared to women whose breast density did not change. Two measures of breast density may provide additional information for assessing breast cancer risk, Vachon concluded.

The current assessment available in most clinical settings is Breast Imaging-Reporting and Data System (BI-RADS), which is not very advanced in the area of measuring breast density, nor was it designed for that purpose.

The study was drawn from the Mammography Health Study, which enrolled 19,924 women who were free of breast cancer, had screening mammograms performed at Mayo Clinic between 2003 and 2006 in Minnesota, Iowa and Wisconsin. From this large group, the researchers selected participants who had at least one additional screening mammogram prior to enrollment. They then looked at clinic and tumor registries in the three Midwestern states to determine if any of these women developed breast cancer after enrolling in the study.

Measures of mammographic density were obtained from the two mammograms, an average of six years apart, for the approximately 1,900 women randomly sampled from the cohort, and from all 219 individuals who were diagnosed with breast cancer during follow-up. In the cancer-free group, 38.6 percent of women had a decrease in breast density, 50.4 percent stayed the same, and 11 percent showed an increase in breast density. In women who developed breast cancer, the percentages were 37, 51 and 12, respectively.

Women who developed breast cancer were less likely to experience a decrease in density in a second mammogram, says Vachon. After adjusting for other potential factors that contribute to breast cancer development, such as age, body mass index, postmenopausal hormones, postmenopausal status, in addition to baseline breast density, the researchers found that women who decreased one BI-RADS category or more over an average of six years were at 28 percent reduced risk of developing breast cancer, compared to women whose density was unchanged.

Breast density can change with time, as evidenced by decreases seen with women going through menopause or using the breast cancer preventive drug tamoxifen. Increases are seen with postmenopausal hormone therapy use. Vachon said the results suggest that decreases in density may translate to decreased breast cancer risk.

Vachon, however, cautioned that the data was not ready for use in clinical practice to inform breast cancer risk, and she stressed the need for standardized measurements of breast density for the assessment of changes in density are needed.

The study was funded by grants from the National Institutes of Health.

For more information: www.aacr.org

Related Content

California Women In Favor of Extending State's Breast Density Inform Law
News | Breast Density | June 15, 2018
A recent survey of California women found that 95 percent of respondents want the state’s breast density inform law to...
Women More Likely to Use Other Preventive Health Services Following Mammography
News | Mammography | June 13, 2018
Medicare beneficiaries who undergo breast cancer screening with mammography are more likely than unscreened women to...
Breast imaging technologies have seen a rapid evolution.

Breast imaging technologies have seen a rapid evolution.

Feature | Women's Health | June 05, 2018 | By Jeff Zagoudis
Breast imaging technologies have evolved rapidly in the last two decades to help physicians detect breast cancers at
Breast Cancer Survivors Not Getting Recommended Number of Mammograms Post-Surgery
News | Mammography | May 24, 2018
Breast cancer survivors are not getting the recommended level of screening post-surgery, according to a newly-published...
FDA's MQSA Accreditation Bodies Approved for Tomosynthesis Accreditation

Image courtesy of Fujifilm.

Feature | Mammography | May 14, 2018
On April 9, 2018, the U.S. Food and Drug Administration (FDA) announced that all four of its Mammography Quality...
Videos | Breast Imaging | May 08, 2018
ITN Associate Editor Jeff Zagoudis speaks with Karen Hou, M.D., breast radiologist at Northwestern Medicine Central D
Computer Error Leads to 450,000 Missed U.K. Breast Screening Invites
News | Mammography | May 02, 2018
Since 2009, approximately 450,000 women around age 70 in the United Kingdom did not receive final breast screening...
Pilot Study Initiated for Blood-Based Breast Test
News | Oncology Diagnostics | May 01, 2018
Overlake Medical Center in Bellevue, Wash., announced it has enrolled 85 patients in a pilot study of a blood test to...
Computers Equal Radiologists in Assessing Breast Density and Associated Breast Cancer Risk
News | Breast Density | May 01, 2018
Automated breast density evaluation was just as accurate in predicting women’s risk of breast cancer, found and not...
Overlay Init