Studies consistently show cancer risk to be four to six times higher for women with extremely dense breasts than for women with low density breasts.
Research studies first established the link between breast density and cancer in 1970. However, public acceptance has been long and hard. “But nobody is arguing about it now,” said Malcolm Pike, professor of preventive medicine at USC Norris Comprehensive Cancer Center and attending epidemiologist at Memorial Sloan-Kettering Cancer Center in New York.
When administering a mammogram radiologist find it helpful to measure and record breast density, as indication of how difficult a mammogram is to read. They find that the denser the breast, the harder it is to accurately read.
Although conclusive findings have discovered a link to breast cancer, health professionals are concerned that this information will only confuse or worry women, since the largest determining factors are still heredity, age and ethnicity.
“I think patients should be told as much information as possible - recognizing they may not be able to use all of it,” said senior biostatistician of Cancer Research and Biostatistics in Seattle William Barlow.
Barlow and others support the need for women to know, arguing this information would encourage women diagnosed with high density breasts to have more clinical exams and mammograms.
The information may also be helpful for women who are deciding whether to use hormone replacement therapy for the relief of menopausal symptoms.
Between 1999 and 2006, breast cancer rates dropped 2 percent, following a 20-year increase. Breastcancer.org reports,
“One theory is that this decrease was due to the reduced use of hormone replacement therapy (HRT) by women after the results of a large study, called the Women’s Health Initiative, were published in 2002. These results suggested a connection between HRT and increased breast cancer risk.”
Breast density is known to change over time, so it is important for women to track their density after every mammogram to help determine their risk of cancer.