As a primary care physician, I have counseled thousands of patients to get cancer screening—blood tests to look for prostate cancer, mammograms to detect impalpable breast cancers, and colonoscopies to find precancerous colon lesions. I’ve even tried to find cancers on physical exam, palpating people’s necks for thyroid growths, for example. The goal of all these screening tests was clear to me—find cancers early and we can get rid of them before they become life-threatening.
All the while, I knew there was a downside to much of my efforts. I was potentially finding “lesions” that, if untouched, would have never harmed my patients. I wasn’t just diagnosing cancer and its predecessors; I was overdiagnosing it. Two studies from Dartmouth physician Gil Welch brings new evidence of the surprising frequency of such overdiagnoses, including surprising data on the epidemic of overdiagnoses in rich countries like the U.S.A.
(To read the rest of this article, please visit Forbes.)
Warning: I am not writing about Angelina Jolie. I am not asking whether women like Jolie, with a strong family histories of breast cancer and known genetic mutations, should consider having bilateral mastectomies. Women like Jolie face extremely high lifetime risks of breast cancer, and thus must make difficult decisions about whether to receive prophylactic mastectomies – surgical removal of healthy breasts in an effort to prevent them from harboring future cancers. I’m not writing about people like that.
Instead, I am writing about women who actually have been diagnosed with breast cancer, but who do not have any known genetic mutation predisposing them to such tumors. I’m wondering in these cases: Is it rational for women to ask their doctors to not only remove the affected breast, but also to perform a contralateral prophylactic mastectomy (hereon: CPM) – a procedure to remove the unaffected breast?
I will tell you my answer right now, so I can walk you through my reasoning without misleading you as to my intentions. I think the decision whether to receive CPM is a very difficult one. Unfortunately, many women make this decision even though they are poorly informed about the pros and cons of the procedure. Given what they believe about CPM, it is totally rational to receive that procedure. But if they were better informed? Then, honestly, I’m not sure so many women would receive that procedure.
But I might be wrong. I expect that CPM decisions, like many decisions most of us make in our lives, are often influenced by highly intuitive thought processes, ones often not influenced by informational campaigns. In short, I refuse to call this decision rational or irrational. Instead, I see it as a really hard call. But it’s a hard call we need to understand, because of what it tells us about the challenges of making good medical decisions.
Let’s start with the information that, plausibly, ought to guide such decisions. When women without genetic mutations (hereon: non-carriers) experience cancer in one breast, their risk of experiencing a cancer in the other breast is usually not dramatically different from the general population risk. To put a number on that: studies put the 10 year risk of contralateral cancer at about 5%. And with new breast cancer treatments, that risk has declined even further. So we are talking about an annual risk of less than a half a percent per year.
A second fact of note: there is no evidence, none, that CPM reduces a woman’s chance of dying of breast cancer. With such a low risk of a contralateral cancer arising, and such aggressive monitoring of such cancer in women with breast cancer histories, most such cancers are found at very early and very treatable stages.
This last fact is important to keep in mind when we look at why women choose CPM. According to a recent study in The Annals of Internal Medicine, more than 90% of women who receive CPM say they did so to increase their chance of long-term survival. Indeed, the majority of non-carriers who receive CPM significantly overestimate the impact the procedure will have on their risk of breast cancer recurrence, and on their chance of long-term survival.
Karen Vogt’s breast cancer journey began like many others, with her breasts painfully squeezed into a mammography machine. At age 52, it was far from her first mammogram, but this scan would be the most consequential by far. It revealed microcalcifications, little areas of breast tissue speckled with deposits of calcium that her radiologist worried were suspicious for a nascent cancer, especially since these specks hadn’t been so conspicuous twelve months earlier. A biopsy proved that the radiologist’s suspicions were warranted. Vogt had a small cancer in her left breast, a ductal carcinoma in situ, as her doctors called it. Stage 0 cancer. What should she do?
This week, medical researchers published a study showing that when women are diagnosed with stage 0 breast cancer, no matter what treatment they receive, their life expectancy is equivalent to women who were never diagnosed with breast cancer. This finding further fuels debates about whether we are screening for and/or treating breast cancer too aggressively. Last year, in fact, a study came out suggesting that even in women 50 years of age and older, annual mammographies are not the life-savers that they were made out to be by medical experts. According to these studies, for every woman like Vogt with a cancer detected by mammography, hundreds more will go through the painful test without any cancer being detected and dozens will experience the harms of “false positive” test results, a term medical experts use to refer to abnormal findings which do not turn out to be a cancer. And just this week, a study was published showing that stage 0 breast cancers are better off untreated
Yet despite increasing evidence of the significant harms of mammography, compared to its relatively modest benefits, many American women dutifully continue to receive annual tests. Why do they remain enthusiastic about mammography? In large part because many women who were harmed by mammography believe the opposite. By identifying non-invasive lesions, like the DCIS discovered in Karen Vogt, mammography has created a community of women incorrectly convinced that the test saved their lives.
Has overuse of mammography created a false epidemic of breast cancer “survivorship?” (To read the rest of this article, please visit Forbes.)
There has been lots written lately about the soaring cost of cancer care. You’re spending a lot on cancer recently in part because of many wonderful new treatments that come with a substantial price tag.
But there has been less chatter about which cancers we are spending money on. Here’s a nice picture illustrating that information. I came across it courtesy of Ryan Nipp:
I’d love to see a breakdown of this information as cost per patient. Please let me know if you have access to those data.
Medical experts now agree that as a result of aggressive screening programs, we have an epidemic of cancer overdiagnosis in the United States. With mammograms finding tiny cancers and PSA tests discovering unpalpable prostate cancers, we are now unearthing some cancers too early for our own good.
What do experts mean by “overdiagnosis,” you ask? First, overdiagnosis is not the same as a misdiagnosis. If a pathologist looks under a microscope and classifies a group of benign cells as being cancerous, that is a misdiagnosis. Such misdiagnoses are an important consequence of cancer screening, causing patients to experience unnecessary anxiety and to undergo unnecessary treatments. Because no pathologist is perfect, aggressive screening programs will, by definition, lead to increases in such misdiagnoses. But these misdiagnoses do not qualify as overdiagnoses, the way experts use the term.
Second, overdiagnosis is not the same as a false positive test result. When a mammogram reveals a suspicious shadow, or when a PSA test is elevated, physicians usually follow up with additional tests, often culminating in a biopsy of the suspected lesion. When that testing reveals that no cancer is present, the screening test (the mammogram or the PSA test) is said to have created a “false positive,” result. It sent out a false alarm. Once again, false alarms are an important side effect of cancer screening. And more aggressive screening programs (yearly mammograms rather than every other year, for example) will necessarily lead to an increase in false positive test results. By some estimates, women beginning annual mammograms at age 40 will face a 50% lifetime risk of a false positive test. In other words, this is a burden of screening that we need to keep in mind when deciding how aggressively to look for a cancer. But false positives are not the same thing as overdiagnoses.
So what does it mean to overdiagnose cancer?
According to cancer epidemiologist Ruth Etzioni: “Overdiagnosis occurs when screening detects a tumor that would not have presented clinically in the absence of screening.” For example, if a mammogram reveals a tiny breast cancer in a 103-year-old woman, a cancer that if left alone would not grow large enough to cause symptoms (much less death) for another decade, that mammogram would probably have overdiagnosed her cancer—if she had never had that mammogram, she would have lived the rest of her life (maybe to 104 or 107-years-old) blissfully unaware that a small breast cancer was growing inside her body.
The example of this hypothetical 103-year-old woman is obviously an extreme one, meant to illustrate what experts mean by overdiagnosis. But it makes one thing clear. Cancer overdiagnoses are cases of real and true cancer. In this hypothetical case, for example, the tumor in this woman’s breast really was malignant. The mammogram did not lead to a misdiagnosis or to a false alarm. Instead, the mammogram discovered a cancer that, while real, would not have ever influenced this woman’s life. In her case, in fact, the diagnosis of this cancer would only act to harm this woman, by causing anxiety and potentially by leading to harmful treatments. (To read the rest of this article, please visit Forbes.)
What would you like first: the good news or the bad news? Let me start with the bad. Life expectancy among patients in the U.S. with thyroid cancer lags behind that in Korea. In fact, the vast majority of patients diagnosed with thyroid cancer in Korea are cured of that illness, a statement I can’t as easily make about the U.S.
The good news? Life expectancy among patients in the U.S. with thyroid cancer lags behind that in Korea.
Okay, I kind of pulled a fast one on you. I tried to mislead you into thinking it is bad when cancer patients in another country out-live cancer patients in the U.S. On the surface, living longer after experiencing a cancer diagnosis seems to be a good thing. All else equal, it is better to survive cancer than to die from it.
But all else is far from equal when it comes to thyroid cancer in the U.S. versus Korea. (To read the rest of this article, please visit Forbes.)
David Asch and I recently published an article in Health Affairs on the challenge of getting healthcare practitioners to stop doing things they are accustomed to doing, even when the evidence that those things are harmful becomes overwhelming. Here is a teaser from that article, and a link to the full piece:
As hard as it may be for clinicians to adopt new practices, it is often harder for them to “de-innovate,” or give up old practices, even when new evidence reveals that those practices offer little value. In this article we explore recent controversies over screening for breast and prostate cancer and testing for sleep disorders. We show that these controversies are not caused solely by a lack of clinical data on the harms and benefits of these tests but are also influenced by several psychological biases that make it difficult for clinicians to de-innovate. De-innovation could be fostered by making sure that advisory panels and guideline committees include experts who have competing biases; emphasizing evidence over clinical judgment; resisting “indication creep,” or the premature extension of innovations into unproven areas; and encouraging clinicians to explicitly consider how their experiences bias their interpretations of clinical evidence.
Mammograms have long been touted as a life-saving preventive test. But recently, people have been re-examining the relative harms and benefits of mammography. This re-examination became quite earnest when the United States Preventive Services Task Force recommended against beginning routine mammography before age 50. Even at later ages, experts are beginning to more thoroughly recognize that the benefits of mammography compete against some very serious harms. Consider the following picture, produced by the website 538, summarizing how mammography influences women at various ages: In short – not a whole lot of lives saved, but a lot of non-cancers cured, even more non-cancers biopsied, and a whole slew of anxiety-inducing false alarms.
I spoke the other day to Melissa Dahl, a writer for New York Magazine. She wrote a really nice piece on what medical professionals call “contralateral prophylactic mastectomy” – when a woman with breast cancer chooses not only to remove the affected breast, but also the unaffected breast in order to reduce the chance of a subsequent cancer. There’s no evidence that this practice reduces breast cancer related mortality. And yet the practice is growing. Here is the beginning of her wonderful essay: It’s potentially the biggest health headline of the week: a new study shows that more women who have developed cancer in one breast are opting for a preventive double mastectomy—even if they’re not at a higher risk for getting the disease in the second breast, and even if that means going against their doctor’s advice. Much of the coverage of the study, published Wednesday in JAMA Surgery, took on a baffled tone, quoting medical professionals who couldn’t imagine a reason beyond anxiety to explain why patients would request an invasive procedure they didn’t technically need—and one that carries medical risks of its own. But even if this decision doesn’t make a lot of medical sense, decades of behavioral science research can offer clues as to why so many women are making it… (Read more at New York Magazine)
In the wake of the horrific floods that struck Colorado recently, many people have debated whether global warming is to blame. The same goes for wildfires that hit that state this summer and for the massive tornado that struck in Oklahoma this spring. In the wake of that tornado, for instance, Senator Sheldon Whitehouse from Rhode Island claimed that Republican opposition to climate change legislation was at fault, for trying to “protect the market share of polluters.” Senator Barbara Boxer was confident about the cause of the terrible twister too: “This is climate change” she said.
The same finger pointing occurred after super storm Sandy, with some people even claiming that global warming could make storms like Sandy into the new normal, occurring as often as every other year, and Governor Chris Christie just as adamantly denying that global warming played any role in this storm.
The problem with these debates is familiar to those of us in the medical community who have followed controversies about breast cancer screening—people mistakenly and all too understandably seek out explanations for individual events when science can only tell us about aggregate truths. For the same reason we cannot tell whether an individual mammogram saved a woman’s life, we cannot determine whether any specific storm is the result of climate change. Instead, we are left with what we can learn from statistics.
Wondering why we don’t know whether a specific mammography test saved a woman’s life? …(Read more and view comments at Forbes)