Last week, Kaiser Health News shed the light on a little known law that requires women who have undergone a routine screening mammogram to be notified if they have “dense breasts”. Written by Barbara Feder Ostrov, the article titled “So You Have Dense Breasts. Now What?” stems from the growing controversy over dense breast notification laws which are currently in place in 21 states, under consideration in another 11 states, and even reaching Congress. The laws raise any many questions as they answer, but the ultimate question of what happens next is vexing policy makers, physicians, and most importantly the very women the law was meant to aide.
In 2004, Nancy Cappello was diagnosed with stage 3 breast cancer. Cappello hadn’t been told that her mammograms showed dense breast tissue, and since her diagnosis she strongly advocated for a new law in her home state of Connecticut. The new law was the first of its kind, defining dense breasts as containing more than 50% fibroglandular (as opposed to fatty) tissue, requiring physicians to offer supplemental whole-breast ultrasound to women with dense breasts, and mandating that insurers cover the additional screening. Ever since there has been a growing movement to educate women about breast density, the risk of breast cancer with dense breasts and the potential role of supplemental screening for breast cancer. About 40% of women have dense or extremely dense breast tissue, which can obscure cancer that might otherwise be detected on a mammogram. The laws therefore have the potential to affect thousands of women.
Advocates have hailed the laws as empowering women to take charge of their own health and note the benefits that additional screening may have for these women. Critics, on the other hand, see numerous flaws in the new laws despite their good intentions. Among the critiques include higher costs, unnecessary anxiety, increasing numbers of unnecessary invasive testing, and treatments that may not save lives or benefit patients. Some worry that the laws may be doing more harm than good. Additionally, the laws vary from state to state; for example, California and many other states require notification but do not require supplemental screening – leaving a woman who received a notification letter in limbo about what to do next.
The root of the problem? There is no medical consensus on whether routine supplemental screening for women with dense breasts is worthwhile. For example, a study in Connecticut performed shortly its notification law went into effect found that supplemental screening was successful in finding more cancers; however, only about three cancers were discovered per 1000 women screened, and the likelihood was low of finding life-threatening cancers. Critics point out that testing different approaches for screening women with dense breasts should be done first and then pass legislation once a consensus has been reached, and not the other way around.
Notification laws add to the already super-charged controversy over breast cancer screening ever since 2009 when the US Preventative Services Task Force changed its recommendations and voted against yearly mammography. Organizations like the American Cancer Society and the American College of Obstetrics and Gynecology viewed the move as “rationing” women’s health care, stating that mammography should begin at 40 and continue annually. These aren’t trivial matters either, breast cancer is the second most common form of cancer among American women and the second leading cause of cancer death. An estimated 231,840 U.S. women will be diagnosed with invasive breast cancer in 2015, and women with moderately dense breasts have about a 20% higher chance of getting breast cancer than women who don’t. Those with the highest-density breasts have about double. To put the numbers into perspective, if an average 50-year-old woman has a 2.38% change of getting cancer in the next 10 years of her life, a woman with the highest density breasts would have a nearly 5% chance of being diagnosed.
But advocates for the US Preventative Services Task Force’s move point out that mammography is far from perfect. Older studies of women who had mammograms in their 40’s suggest that the test reduces mortality by as much as 30 to 40%, but newer research has decreased that benefit to around 15%. Researchers broke down the numbers as follows: if 10,000 women aged 40 have mammograms every year for ten years, an estimated 190 will be diagnosed with breast cancer. Of those, the test will save about 5. Roughly 30 will die because their cancer will prove too aggressive. For the rest, mammography won’t make a difference, in large part because their cancers are slower growing, will never become invasive, or because treatments have improved, making early discovery through mammography less urgent. Due to the false positive rate of mammography, more than 6,000 of the cancer-free women will be called back with at least one false positive in ten years likely resulting in unnecessary biopsies. Any abnormalities that are found will almost certainly be treated as if they could be deadly, exposing women to radiation, surgery, chemo, and hormone therapy, all of which have their own set of risks.
The bottom line is that informing women of breast density may empower them and create informed decision makers, but on the other hand being informed requires telling them the risks and benefits of that new knowledge.