A doctor examines a mammogram. The new law requiring doctors to tell patients… (Ben Edwards / Getty Images )
Doctors in California will soon have to tell a patient if a mammogram reveals she has dense breasts. They will have to explain that breast density is associated with a higher risk of breast cancer, that it makes mammograms harder to read and that “a range of screening options are available.”
The new law, which will go into effect April 1, 2013, follows similar ones that have passed in Connecticut, Texas, Virginia and New York. It is endorsed by a variety of groups, including the California Radiological Society, the California Nurses Assn., California affiliates for the Susan G. Komen Foundation and Planned Parenthood Affiliates of California. Sponsored by California State Sen. Joe Simitian (D-Palo Alto), it was recently signed by Gov. Jerry Brown.
Breast cancer risk is affected by a variety of factors, among them the density of breast tissue (meaning more glands and fibrous tissue relative to fat). Dense breasts also are harder to read on a mammogram because the dense tissue shows up as white, the same way a tumor does.
Here’s more about the science of breast density in an article written by freelance writer Karen Ravn in 2010. As she notes, the relationship between breast density and breast cancer was observed as early as the 1970s but the link took a while to be accepted in the medical community and has generally not been reported to women because it was considered a) mostly of interest to radiologists who had to read the mammograms and b) giving women the information would “serve little purpose other than to confuse or worry them, since it’s largely determined by factors outside of their control (such as heredity, age and ethnicity).”
Some researchers and doctors have argued that it should be reported to women anyway. After all, noted one of them in Ravn’s article, a lot of the risk factors for breast cancer are ones we can’t do anything about, and yet women get told about them anyway. Plus the knowledge could prompt those who have dense breasts to have more exams or opt for an MRI, which allows tumors to be seen clearly even when breast tissue is dense.
But other specialists worry about laws that require notification about dense breasts. Many don't think that more screening and more testing is necessarily what women need in the fight against breast cancer.
In an article published in Radiology Today in August, specialists voiced concerns that such laws “may complicate women’s screening decisions, lead to confusion about screening follow-up, increase the potential for false-positives, and create additional healthcare costs.” The article notes that breast density scores can vary in different specialists’ hands, and that alternative methods of screening (ultrasound and MRI) may lead to more false-positives -- resulting in unnecessary tests -- and may not be covered by a woman’s health insurance.
Thus, though the American College of Radiology supports including information about breast density in the mammogram report sent to physicians, it doesn’t come out and support mandatory notification to patients.
“While the ACR is not opposed to including breast parenchymal information in the lay summary, we urge strong consideration of the benefits, possible harms and unintended consequences of doing so,” it writes in its position statement.
Here’s what breast doctor Susan Love (of the Dr. Susan Love Research Foundation) has to say about the breast density issue (and the new law) on her blog. She notes that the issue of breast cancer diagnosis and breast cancer death are turning to not be the same thing. She cites a six-year study published in the Journal of the National Cancer Institute earlier this year that found women with dense breasts are no more likely to die from breast cancer than those whose breasts are not dense. In fact, the greatest risk of death in that study was for women whose tumors were large and in women with fatty breasts.
“Could it be that dense tissue represents a local microenvironment that promotes cancer development, but not spread? Or that the low breast density seen in obese women creates a microenvironment that makes tumors more aggressive? That is something we need to study. ... Maybe dense breast tissue increases the risk of getting cancer, but not dying of it. If this is true, it might mean we don’t need to treat the tumors of all women with dense breast tissue the same way, or the same as we would a woman with fatty breasts."