Mammogram wars, round 2

As if the furor over a new recommendation to give mammograms less often to women in their 40s wasn’t enough, a recommendation also was issued last week by the American College of Obstetricians and Gynecologists calling for less-frequent Pap tests to screen for cervical cancer among women.

The ACOG’s reasoning:

Screening before age 21 should be avoided because women less than 21 years old are at very low risk of cancer. Screening these women may lead to unnecessary and harmful evaluation and treatment.

Cervical cytology screening is recommended every 2 years for women between the ages of 21 years and 29 years. Evidence shows that screening women every year has little benefit over screening every other year.

The public’s response has been remarkably muted. The ACOG’s recommendation is generally similar to the U.S. Preventive Services Task Force’s new recommendation on mammography. Both reviewed the existing data. Both weighed the relative risks and benefits of screening among various age groups, and both concluded the benefits aren’t significant enough to warrant annual screening among younger women – in the case of mammography, among women in their 40s, and in the case of the Pap test, among women younger than 21. (In case you’re wondering, the USPSTF’s position on cervical cancer testing is to screen among women within three years of the onset of sexual activity or age 21, whichever comes first.)

I don’t hear the sound of opponents sharpening their knives over the prospect of fewer Pap tests for younger women. Nor did I hear the pitchforks come rattling out of the shed last year when the USPSTF issued a recommendation against screening for prostate cancer among men older than 75.

When it comes to mammograms and breast cancer, it seems the discussion invariably becomes both personal and political. Indeed, it’s hard to make it impersonal. Breast cancer is the most common type of cancer found among women. Most of us don’t have to look far to find someone we know who has been diagnosed with it – including plenty of women in their 40s.

It doesn’t help that mammography has always been a somewhat imperfect tool, or that the benefits of screening for younger women have persistently inhabited a gray zone. It makes it harder to judge what’s the right thing to do.

Reasonable people can disagree about the USPSTF’s new guidelines. What’s frustrating, and even damaging, is the clamor over this. It has gotten so loud that it’s threatening to drown out rational thought.

For starters, people keep referring to the USPSTF’s new guidelines on mammography and breast self-examination as a new study. It’s not; it’s a review of the existing literature and a judgment call on the basis of data we already have. No one has broken any new ground here. The benefits of mammography among women in their 40s have been studied before and the benefits, weighed against the possibility of unnecessary further testing, overdiagnosis and possible harm, have never been particularly clearcut.

I’ve seen repeated statements that the new guidelines mean we’ll be abandoning mammography for women in their 40s. This is inaccurate. I’ve seen people charge that this was all about the money, when in fact the cost was not part of the USPSTF’s analysis. I’ve even seen people attack the USPSTF’s recommendations for women over age 75 as ageism and tantamount to sentencing older women to death. It’s rubbish; the guidelines merely say the benefits of mammography in this older age group are not clearly established.

And at the risk of sounding like a broken record, I’ll say it again: Anecdotes, even the most personal of personal stories, are not the same thing as evidence. There’s value in anecdotes; they illustrate, they illuminate, they put a human face on what would otherwise be a dry collection of statistics. But they’re not a substitute for good science.

A reader this weekend pointed me towards this transcript of an interview last week on PBS. It’s worth reading for its clear-headed look at the issue. One of the highlights comes from Dr. Diana Pettiti, vice chair of the USPSTF panel:

The task force is not saying there’s a cutoff. It is not recommending against ever screening women in their 40s.

The task force has made a recommendation against routine screening, that is, screening where a postcard comes in the mail and the woman is told that she must be screened every year. Again, we do not disagree at all about the need for women to make an informed choice about being screened at any age.

That conversation should begin in the 40s. And women who want to be screened, after understanding what those benefits might be against the harms or the negatives, should be screened. We don’t disagree. There is no cutoff. There was no magic number. And this was not a cost-effectiveness analysis.

For what it’s worth, I think the U.S. Preventive Services Task Force could use a savvy public relations consultant. The American public is not used to hearing about the down side of screening – any screening, not just mammography. We haven’t yet absorbed the fact that there are limits to its usefulness. It’s a message that has been out there, to some extent, but it doesn’t seem to be reaching very far. Last week’s recommendation probably caught most people by surprise, and they weren’t ready to hear it.

We should have been ready for it, however. At the very least, we should have been receptive and willing to be at least somewhat rational. I mean, come on, folks. This is science. This is epidemiology. Do we want our health care decisions to be based on the available evidence, or do we prefer to simply throw things at the wall and hope some of them stick?

Here in the United States we do an enormous amount of screening. Some of it, I’m sure, is very beneficial. But we do owe it to ourselves to understand the facts and the tradeoffs. And we need to be asking the hard questions and remain open to the answers, even if we don’t like what we’re hearing.

Added: From the New York Times, here’s an in-depth look at how the U.S. Preventive Services Task Force gathered the data and arrived at its recommendation on mammography.

Update, Nov. 24: Is there likely to ever be a final word on the benefits of mammography among women in their 40s? This has been a long-standing controversy, with expert views on both sides of the fence. An article in MedPage Today offers a historical perspective on the issue.

West Central Tribune file photo by Bill Zimmer

5 thoughts on “Mammogram wars, round 2

  1. Good blog, Anne. I had read both the PBS interview and the new york times article on the indepth work done on the study. I remain in my “camp” :) Passionate beyond words. Statistically significant and plain old significant are two different things to many when discussing human lives. That is a problem when extrapolating data from studies and models – it doesn’t take into account the human factor of each number. I agree this panel would have benefitted from hiring a PR spokesperson. I’m heading in to see my doctor tomorrow – physical time. I am interested to hear what she says about this. I want my annual mammogram and will not stop doing my monthly self-exams (crazy). It’s the best I can do for myself and my family – my young kids. I don’t want to miss anything if I can help it!!!!! How can I skip it – or stop watching!?! I’ll try to open my mind on the subject but I’m staying on this schedule until something better comes along! I refuse to be a statistic on the wrong side because I didn’t try take care of myself the best I believed I could.

  2. Here’s another discussion that was on NPR. It discusses some of the actual data that was used in review which is not even known to be the most current – based on latest technology. There is also data -meticulously kept on Mamms in Sweden that has promising stats on the benefits of mamms. You may find some of those points of discussion interesting – or maybe you have heard them already. It is a hot topic at coffee for sure! Most are totally for the mamms at 40.

    http://www.npr.org/templates/story/story.php?storyId=120562878

  3. My obsession continues:

    Some take issue with the new guidelines. With these recommendations, the task force has made “a value judgment that’s subject to discussion and interpretation,” says Len Lichtenfeld, deputy chief medical officer for the American Cancer Society, which is sticking to its recommendation that women begin annual screening mammograms at age 40. Harms are tricky to measure. It’s hard to quantify the psychological impact of additional tests and biopsies, for example. And estimates of overdiagnosis generally range only between 1 percent and 10 percent, according to the review consulted by the USPSTF. (Monetary costs weren’t considered by the task force, says USPSTF Vice Chair Diana Petitti.) Lichtenfeld is also concerned about using computer models as the basis for the every-other-year recommendations, since so much is at stake.

    Marisa Weiss, a Philadelphia oncologist and founder of Breastcancer.org, says the task force’s conclusions were based on outdated assumptions about treatment and mammography. For example, studies show that digital mammography is more accurate among young women, but the USPSTF discussed only the standard film mammography. And it figured in certain harms that have been ameliorated over the years with procedures such as core biopsies rather than the more invasive open biopsies, as well as tests that can predict which women are likely to benefit from chemotherapy and which can skip it. She worries these recommendations will result in young women being entirely bypassed, so that women in their 50s will be diagnosed at later stages of cancer and will need more treatment.

  4. Well, this issue certainly seems to be bringing out people’s inner pit bull.

    It is valid to ask the question: Has our philosophy and approach to screening led to overtesting, overdiagnosis and overtreatment? We know it has, although the extent to which this is happening is subject to debate and is probably impossible to accurately quantify.

    We need to be looking at these issues; we can’t afford not to. But society seems unwilling to confront it or to even admit the possibility that perhaps we’re overdoing it or that screening is an imperfect predicter of outcomes.

    There was an opportunity here to start having that conversation, but I fear we have missed it.

    Women can and do get other types of cancer for which there is no reliable screening or early detection. I can’t help wondering, where is the passion for them? What about women who are uninsured? As far as they’re concerned, this whole discussion is academic. They don’t even have access to screening, much less followup care if something abnormal were to be detected.

  5. Fair enough. And yes, pit bull could describe me -though usually just in the blogging world! :)

    I will wait on the final say from the consensus of experts in the medical field who have currently rejected the USPSTF panel recommendation on mamms and self-exams. Medical experts from Sloan Kettering, ACS, Mayo, Northwestern and on and on are concerned the the preliminary information they saw in the data. They will now review the data themselves with experts and give their opinions on it – how the study of studies was done and what info was used.

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