Diagnosing Breast Cancer: A Dense Dilemma
The passage of the Affordable Care Act (Obamacare) and the reelection of President Obama was cause for real hope among those in pursuit of the Holy Grail in medicine: higher quality at lower cost. However, with the passage of what is called the Breast Density Bill in several states, the quality cost equation seems doomed on both ends. The Affordable Care Act mandates coverage of screening mammograms, without co-pay or deductible, but the Breast Density Bill is destined to push utilization of “non-beneficial” imaging, ie imaging that does not clearly save lives, even further.
The new law authored by Sen. Joe Simitian, was signed into law a couple of months ago in California. Beginning April of next year, the bill requires facilities that perform mammograms to include a special notice, within the imaging report sent to patients, regarding the high density of breast tissue and the benefit of additional screening tests. The notice will state the following; “Because your mammogram demonstrates that you have dense breast tissue, which could hide small abnormalities, you might benefit from supplementary screening tests, depending on your individual risk factors”.
The supporters of the bill make the ethical argument that women have the right to know about how dense breast tissue can obscure mammogram visualization, and should be offered additional test such as ultrasound and magnetic resonance imaging (MRI) to alleviate the doubt. To provide further support, the SOMO INSIGHT Breast Cancer Screening Study is a nationwide research effort to evaluate if automated breast ultrasound done together with routine screening mammogram is more accurate in detecting breast cancer in women with dense breast tissue. The study is funded by U-Systems, Inc.; the Silicon Valley based company responsible for the sophisticated and expensive ultrasound technology used in this study. Thus, one cannot deny the possibility of patient interest being confounded by financial interest.
The patient advocacy movement around breast cancer has been championed by several well-known non-profits, such as Susan B Komen, Are You Dense Inc. and even endorsement by the National Football League. Yet, the confusion about screening is reflected in the variability of requirements for insurance coverage between states. For example, while Texas and Mississippi require screening mammograms to be covered for all women 35 and older, Utah has no coverage requirement and several other states do not require coverage until age 40.1 Awareness of breast cancer screening is necessary, and the complexities of picking up certain irregularities certainly deserve attention. However, the patient’s “right to know” should also include the right to know about “over-diagnosis”. Interestingly enough, the term is defined in the bill as one of the harms of mammography screening and is “the identification of cancers that will not become clinically significant, leading to unnecessary treatment”. This issue, which is often down-played for various reasons, is troubling, yet we keep recommending more tests.
According to Jessica Leung, MD a mammographer and member of the Society of Breast Imaging “Large-scale randomized controlled trials over several decades have proven that screening mammography reduces breast cancer mortality. Though mortality data are not available with respect to adjunctive screening with ultrasound or MRI, recent studies have shown that an increased number of favorable-prognosis breast cancers may be diagnosed with these imaging methods. ” In other words, ultrasound or MRI will certainly pick up more early, “favorable prognosis” cancers, even in dense breasts. But will they save lives?
Not necessarily, according to Dr. H Gilbert Welch from the Geisel School of Medicine at Dartmouth College.2 Based on Surveillance Epidemiology and End Results (SEER) data, if we follow 2500 women, of 50 years of age, undergoing annual mammography for 10 years, 1 – 2 of them will avoid cancer death. About a thousand of those women will have at least one false positive result during that time, and about half of them will end up getting at least one biopsy. But what most people don’t know, is that 5 – 15 women out the 2500 being followed, will end up being “over-diagnosed”, and receive unnecessary treatment for a cancer that would not have led to harmful clinical symptoms otherwise. An estimated 70,000 women were over-diagnosed in 2008 itself, accounting for 31% of all breast cancer diagnoses that year.3 Welch and his colleagues believe that mammography, the gold standard test in breast screening over-diagnoses many cancers that would not have caused harm to the patient if left undetected. To extrapolate this reasoning to ultrasound and MRI, which are more likely to pick up “something” even in dense breast tissue, the problem balloons.
The mandate proposed by the bill is based on a justified intention to inform the patient about the risk of high density breast tissue. But there needs to be caution, because high breast density is not a proven independent risk factor for breast cancer, and only women with specific risk factors (such as family history, genes) may truly benefit. False positive and over-diagnosis rates are expected to be much higher for breast ultrasound and MRI, and defensive medicine will prompt physicians to recommend more testing in fear of liability. This is the template for how our health care costs spiral out of control and patients will not necessarily benefit from it. Paying for the extra tests may be difficult for patients on certain health plans, like Medicaid, and a possible state-mandated coverage requirement for additional testing can lead to higher insurance premiums.
A mandate is not the solution; but if it prompts an unbiased discussion between the patient and physician, then it may accomplish the ethical goal of informed patient choice. Engaging patients in the decision making process, informing them of the best evidence, and tailoring the plan of care according to their individual characteristics, risks and expectations is the right approach to the dilemma of dense breast screening.
-Anubhav Kaul, MD and Jennifer Brokaw, MD
Dr. Anubhav Kaul is a recent medical graduate from Ross University School of Medicine, and he is currently pursuing a Masters in Public Health at The Dartmouth Institute of Health Policy and Clinical Practice.
Dr. Jennifer Brokaw is the Founder of Good Medicine Consult and Advocacy and the editor of the Good Medicine blog. She is married to a mammographer.
1 “Paying for Breast Cancer Screening.” Breast Cancer: Early Detection. The American Cancer Society, n.d. Web. 27 Dec. 2012. http://www.cancer.org/cancer/breastcancer/moreinformation/breastcancerearlydetection/breast-cancer-early-detection-paying-for-br-ca-screening.
2 Welch HG. Screening mammography–a long run for a short slide? N Engl J Med. Sep 2010; 363(13).
3 Bleyer A, Welch HG. Effect of three decades of screening mammography on breast-cancer incidence. N Engl J Med. Nov 2012; 367(21).