A newly-published study in JAMA Internal Medicine claims to substantially quantify the benefit and harm of mammography screening by focusing on three outcomes: reduction in cancer deaths, false-positive results, and overdiagnosis. But the ability of these parameters to accurately determine screening guidelines is untested, and asserting their combined power only adds to the confusion. And although the authors admit that new clinical trials are needed to provide women with the real answers on mammography benefits, the irresponsible take away from this study is that there is little benefit gained and much harm done by this established method of early detection.
There is no disputing that treatment advances have resulted in fewer breast cancer deaths. But there should also be no argument that catching a cancer early is extremely advantageous -- often requiring treatment that is less invasive and less costly on all counts: physically, emotionally, and financially.
There is also agreement that broad utilization of regular mammography is likely to result in overdiagnosis and overtreatment. Many of these early cancers may never progress and become life-threatening. But the truth is that until we have reliable tests that accurately distinguish the fatal cancers from the clinically-insignificant cancers that can be left untreated, some women will be over treated. That is the unfortunate price we must pay to avoid the unforgiveable: missing the diagnosis of treatable, life-threatening breast cancers -- sacrificing precious lives, causing enormous suffering, and resulting in many lawsuits that greatly inflate today's healthcare costs.
While no one wants to undergo needless medical treatment, it's better to over treat if a cancer is caught at an early phase than to require aggressive, debilitating, and often deforming treatment once a cancer has reached a more advanced -- and more likely deadly -- stage.
Patients often ask me, "If it were you, what would you do?" As both a doctor and a patient, I'd prefer to run the risk of over treating an early stage of breast cancer rather than cut back on early detection and assume that modern-day treatment advances will save me when a "real" and "must be taken seriously" type of cancer shows up.
Even with today's treatment advances, which have significantly improved survival, you have to find the cancer in order to treat it. The JAMA author's Report Card, attributing most of the survival benefit to treatment (over early detection), was based on results of women treated in early stages of disease found through early detection methods -- with mammography finding most of them. It's a big leap to assume that today's treatments would save as many lives if women were diagnosed with cancer in later stages, as would occur if mammography screenings were substantially reduced.
Basing mammography guidelines on a totally untested "comfort level" of the chance of saving a life vs. the risk of a false positive is unconscionable. Casting future guidelines for the diverse American female population based on meta-analyses of outdated mammography techniques performed on largely homogeneous Scandinavian, British, and Canadian women is also irresponsible.
We can and must do better. Future mammogram recommendations need to be based on accurate measures of proven cancer risks, as well as the risk of false positives using the new detection technologies now available. We need much more accurate predictors of risk that go well beyond the current common risk factors of family history, genetic mutation results, and past biopsies showing atypical cells. Risk assessment also should address other factors such as mammographic density, age of menarche and menopause, age of first birth, use of certain pharmaceutical hormones, weight, and physical activity levels.
Yes, clinical trials can help answer some of these difficult questions. But it will take a diverse population's full participation in well-designed studies to provide women with a better answer to the question, "What should I do?" Until then, we should err on the side of early detection and early treatment.