By Bonny McClain
The media has a role in helping to prevent overdiagnosis and excessive care in medicine. I write a popular blog and can empathize with how hard it can be to resist the “catchy” headline or teaser to help drive readers to your article. The problem is that while evidence advances our understanding, more often than not articles are shared without being read. A short headline becomes fact and misrepresents the science.
Ray Moynihan and colleagues discussed specific drivers of overdiagnosis in an article published a few years ago in the British Medical Journal (BMJ 2012;344:e3502 doi: 10.1136/bmj.e3502; 29 May 2012):
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Technological changes detecting ever smaller “abnormalities.”
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Commercial and professional vested interests.
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Conflicted panels producing expanded disease definitions and writing guidelines.
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Legal incentives that punish under-diagnosis but not over-diagnosis.
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Health system incentives favoring more tests and treatments.
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Cultural beliefs that more is better; faith in early detection unmodified by risks.
Figure 1
Why is this important?
At the annual Preventing Diagnosis conference in September, Ronald Adler, MD, and Stephen Martin, MD, who are on the faculty at the University of Massachusetts Medical School, presented “Think Before You “Pink”: Re-Designing Cancer Screening Educational Campaigns.” Their title is a nod to the Think Before You Pink education project sponsored by the advocacy group Breast Cancer Action. With their permission, here are two graphics they used in their presentation.
The conventional wisdom about the benefits of cancer screening has a lot of uptake in the community, but when we look at the data, the claims don’t stand up. For example, cancer is not a single disease, it doesn’t always mean death, and cancer found by screening isn’t necessarily cured.
Cancers are in fact heterogeneous, and at the individual level it often is impossible to predict how a particular cancer will evolve or respond to treatment. Even within a single organ, such as the pancreas or prostate, the heterogeneity can mean the difference between being lethal, potentially treatable or indolent. The most important yet often ignored fact is that there are always harms associated with cancer screening and treatment, even with the best of intentions.
Advances in research have improved our ability to detect cancer. If we report five-year survival rates, these ranges have definitely been extended, but are we truly measuring a benefit? We do not observe a decrease in mortality rates coinciding with increased detection. The mortality rates have remained relatively flat across the board.
Figure 2: Incidence rates vs. mortality rates in cancer
Key facts
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Cancers are heterogeneous.
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Cancer screening is less beneficial than it seems.
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Overdiagnosis is an inevitable consequence of cancer screening.
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Cancer screening causes harms.
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Direct injuries.
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False alarms.
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Unnecessary treatment of indolent cancers.
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Futile treatment of highly aggressive cancers.
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Financial/Opportunity costs.
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Cancer screening decisions should be made by patients after a process of shared decision-making in which they come to understand the projected benefits and harms and consider their own values and preferences.
What we need as a society is education for patients, clinicians and policy-makers regarding cancer heterogeneity, the limitations of screening tests and anticipated chances of benefits and harms. To better promote and facilitate shared-decision making, it is critical to present meaningful representation and analogies when discussing cancer prevention and care. Here are some important messages to communicate in journalism stories
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There are many different cancers; they range from harmless to lethal.
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We can screen for some of them.
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Screening programs are imperfect as they may:
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Fail to identify cancer that is present.
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Falsely identify benign conditions as cancer.
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Successfully identify cancers, which may be:
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Indolent or potentially lethal.
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Treatable or not.
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Cancer screening is a personal decision.
Bonny McClain (@graphemeconsult) is a freelance health economics writer, medical writer, published author, public speaker, and insight analyst with two popular blogs, www.dataanddonuts.org and www.alzheimersdiseasethebrand.com. Her latest book, “Improving Numeracy in Medicine,” is available for pre-order on Amazon.
