Mammogram Theater: A Visual Aid For Medical Decision-Making

With a title like "mammogram theatre" you would wonder if this post is meant to poke fun at the elaborate song and dance of mammography; we have spent years promising women that "early detection is key," only to realize that screening mammography cannot do what we originally hoped it could (but many still pretend it can).

Of course women want their breasts and lives saved. But the information on the benefits of mammography has been largely overstated in part due to cognitive biases (like lead-time bias, base-rate fallacy, etc), and the risks are too often left out of the conversation.

Every test has risk and benefits, but it can be challenging to decide if a test or treatment is right for you or your patient when there is too much information, experts disagree when they review the same studies, and the media has a constant see-saw back and forth of "yes" and "no" headlines that seem only to confuse. It can feel a bit like ping-pong, following the discussion back and forth. It's not really fair to ask patients to make sense of all this.

So yes, the promise of benefit of mammography may have been a bit of dramatization, but the theatre I speak of is a literal one. 

Dr. Andrew Lazris is an American internist who partnered with environmental scientist Erik Rifkin to popularize a simple, easy way of showing how many are helped and harmed by common tests and procedures.

Lazris and Rifkin have developed a tool to give people a realistic way of evaluating 'hope and worry;'

Their "benefit-risk characterization theater" images vividly show the odds, based on solid research. (read more on NPR)

This is a tool to help doctors and patients have informed discussions about the risks and benefits of breast cancer screening with mammography, to engage in shared-decision making on the topic. Take a look:

This tool has been added to the "hands-on tools" section of this website, where you can find other tools like it.

Source: http://www.npr.org/sections/health-shots/2...

Better informed women probably less likely to choose mammography

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An interesting article was published in the latest Lancet: Use of a decision aid including information on overdetection to support informed choice about breast cancer screening: a randomised controlled trial.

In brief, women who got information about the risk and possible harms of breast cancer screening (by mammography) were less likely to intend to be screened. The study didn't go on to look at what the women actually chose (only what they intended to choose). However, it still confidently suggests that women who have all of the information are less likely to get screened.

Contrast this informed approach with the classic approach from the well-intentioned doctor: "You need a mammogram to screen for breast cancer. Here is the requisition."

It is not wrong to say no. (These are the words of Dr Iona Heath - well ahead of the curve - in the title of a  BMJ paper in 2009 regarding this same topic).

It is not wrong to say no. And the more you know, the more likely you'll say no. 
 

Not sure what to do for yourself?
Not sure how to start discussing this with patients?
 

- Here is a Canadian resource to help you decide if Mammography is right for you; it's not perfect but it is a start

- Below is an icon array from the Harding Center for Risk Literacy that helps visually represent the benefits vs. harms of mammography:


Source: http://www.thelancet.com/journals/lancet/a...

How can you have an overdiagnosis of cancer? Either it's there, or it's not.

"How can you have an overdiagnosis of #cancer?  Either it's there, or it's not." – @susila55

[click to expand]

Rates of new diagnosis and death for five types of cancer in the US, 1975-2005. Adapted from Welch and Black, in Preventing overdiagnosis: how to stop harming the healthy. BMJ 2012; 344:e3502

In response to tweets about a potential for overdiagnosis in thyroid cancer cases, a twitter user, Susan Burke Mangano (@susila55), asked this question.

There have been many articles lately on overdiagnosis of almost all kinds of cancer. Our twitter discussion was mainly around thyroid cancer (with Dr Gilbert Welch leading in publications eg. Current Thyroid Cancer Trends in the United States).

Whether breast or prostate, thyroid or renal, the conclusions are generally the same: we are diagnosing more and more cancer, but it is not affecting mortality rates.

How? What?

"There is an ongoing epidemic of thyroid cancer in the United States. The epidemiology of the increased incidence, however, suggests that it is not an epidemic of disease but rather an epidemic of diagnosis." – Welch et al.

I'm not going to explain it here myself since it has already been done well in many places, the most straightforward of which is this video/article combo, by the Wall Street Journal.

I highly recommend you take a look.

Read Some Cancer Experts See 'Overdiagnosis,' Question Emphasis on Early Detection in the Wall Street Journal.

 

* As they have just locked this article (you need a WSJ subscription or institutional access eg. university library account), I will include a few pertinent quotes here:

 

While it's clear that early-stage cancers are more treatable than late-stage ones, some leading cancer experts say that zealous screening and advanced diagnostic tools are finding ever-smaller abnormalities in prostate, breast, thyroid and other tissues. Many are being labeled cancer or precancer and treated aggressively, even though they may never have caused harm . . .
"We're not finding enough of the really lethal cancers, and we're finding too many of the slow-moving ones that probably don't need to be found," says Laura Esserman, a breast-cancer surgeon at the University of California, San Francisco. . . .
"Unfortunately, when patients hear the word cancer, most assume they have a disease that will progress, metastasize and cause death," the group wrote in the journal Lancet Oncology in May. "Many physicians think so as well, and act or advise their patients accordingly." . . .
Overdiagnosis--the detection of tumors that aren't likely to cause harm--is now a hot topic in other cancers as well. A growing volume of studies estimate that as many as 30% of invasive breast cancers, 18% of lung cancers and 90% of papillary thyroid cancers may not pose a lethal threat. . . .
"Everyone says they'd be willing to be overtreated if it means not dying--but that's a big fallacy," says Dr. Esserman. "By treating 1,000 people who have low-risk disease, we're not going to save the one person with aggressive disease." . . .
Says Dr. Esserman: "We need to start testing some of these ideas, rather than just fighting over them. People are afraid to do less. We want to figure out how to do less safely."
- Melinda Beck, WSJ