Mammograms are considered the gold standard in finding breast cancer in women, but one of the leading experts in the disease says the very structure of breasts could hinder the procedure.
Dr. Paula B. Gordon is the Medical Advisor for Dense Breasts Canada, a non-profit composed of breast cancer survivors and healthcare professionals who are raising awareness about the risk of breast density in diagnosing breast cancer. Dr. Gordon’s research has led to several breakthroughs in how the disease is diagnosed. She chairs several committees and has received many awards for her work, including the Order of British Columbia. Her research has shown that the density of breasts can cause cancer to go undetected until it’s too late.
But what is breast density? Every woman’s breast is composed of fat and tissue, and each one has different proportions that vary across the population. Density can be determined on a mammogram or through software, according to Dr. Gordon. Density is then arranged in category, where A and B are considered non-dense, and C and D are. “Over 40 percent of women over the age of 40 have dense breasts,” she adds.
The problem with breast density is that it can hinder a mammogram’s ability to detect cancer. Cancer shows up as white on the readout, but so does dense breast tissue. Dr. Gordon says in that case, the cancer is masked and is not visible on the mammogram.
She adds that dense breasts are themselves an independent risk factor for breast cancer. “Cancer occurs four to six time more often in women with the highest level of density than in women with the lowest level,”. She adds density is a more prevalent risk factor than family history.
In addition, high density results in higher rates of interval cancers, where a woman is diagnosed with cancer after her last mammogram was negative. “Usually, the woman finds a lump or other symptom that leads to testing when the cancer is found.” Dr. Gordon says interval cancers are 13 to 18 times more common in women with dense breasts. They are larger, more often lymph node-positive, and more aggressive, leading to a poorer prognosis.
Women with dense breasts need to be proactive in their cancer screening, according to Dr. Gordon. In many provinces, information on density is included in your mammogram results, but if not, you can always ask your doctor. She also suggests doing regular self-examinations, learn the different ways breast cancer can appear, continue having regular mammograms, and modify the lifestyle factors that affect cancer risk.
Dr. Gordon also urges women to have a discussion with their healthcare provider about breast density. Consider asking how your density impacts your breast cancer risk, and how to address it. Do you have other known risk factors, what are the most appropriate imaging procedures, and what is the overall risk?
“If you wish to have supplemental screening in some provinces, you may need to advocate for yourself;.” Dr. Gordon adds Dense Breast Canada has advocacy toolkits and conversation tips available on their website.