Science, medicine, and politics mix in new mammography and stem cell guidelines

Today's news included two stories that both illustrate how politicians almost always get science wrong. It never seems to be a good thing when politicians sink their teeth into a scientific or medical question: they are only too happy to distort the facts to achieve their political goals.

First, the new mammography guidelines. This was all over the news two weeks ago: an official federal advisory panel, the U.S. Preventive Services Task Force, recommended that women between 40 and 50, who had no risk factors for breast cancer, not have annual mammograms. This caused a firestorm of criticism from many quarters, because the previous guidelines recommended annual screening. The panel determined, after looking at data from the past decade and more, that the risks of excessive screening (many more false positives, and the resulting biopsies and even surgeries) were not justified by the small number of additional cancers detected.

This is a complex issue, and many other bloggers wrote about it, so I'm not going to discuss it in detail. My overall impression was that the panel weighed the evidence and made their recommendations based on the best available science, and I think their decisions were good ones. I'd also note something that the media seems to have missed: about ten years ago, when another panel was debating similar recommendations, there was tremendous political pressure to make annual screening the official policy.


Rather than discuss this, today's story, as headlined in the Washington Post, is "Mammogram guidelines debated along party lines as panel members are grilled." Yes, Congress is having a hearing, and they've brought the task force in so that members of Congress can talk. They're not really "grilling" the panel - instead, the House members are making speeches to express their opinions. None of these opinions have anything whatsoever to do with science. The Republicans are using this recommendation to claim that this demonstrates how the federal government is going to "ration" health care. They have seized on the task force's report to make a political point, and they don't care whether or not the recommendations make sense. Not surprisingly, the Democrats are defending the panel's recommendation and saying it was not driven by cost, or by the health care debate. Even though I agree with them, I don't think they really care either - they just want to pass their health care bill.

One thing I'm sure of is that politicians have no credibility on this issue, one way or another. But they're having their hearing, and they seem eager to use this complex question to make over-simplified claims that have nothing to do with whether a woman should get screened annually or not. [Update: a day after I posted this, they added an amendment to the health care bill that guarantees insurance coverage for annual mammograms for women ages 40-50. Maybe that will quiet down the politicians.]

Other groups have jumped into the debate, including the American Cancer Society and the American College of Radiology, who continue to recommend annual screening. But these groups make a considerable profit from mammography, so they have a clear conflict of interest - although it would be nice if I could just trust them. But I can't.

The second story today is a good one: NIH just approved 13 new stem cell lines, the first ones approved since Pres. Bush essentially shut down stem cell research in the U.S. back in 2001. Many more cell lines should be approved soon, which is great news for stem cell research. Most of the opposition to stem cell research has come from Republicans (with some notable exceptions), while support came from Democrats. Meanwhile, the U.S. has fallen behind in what is probably the most exciting, promising area of medical research in the past couple of decades.

Every time there's a major story on stem cell research - and today was no different - the media goes to Richard Doerflinger, of the U.S. Conference of Catholic Bishops, for a quote saying what a terrible tragedy this is. (To be fair, the AP news story didn't quote him.) What I find particular annoying about this guy is that he's constantly telling us about science, as he did today, when he said "the science is all moving in the other direction," toward induced pluripotent stem cells (IPS cells). Doerflinger is not an expert on stem cell science, and he has a single-minded agenda, which is to halt research on embryonic stem cells - so in my mind, he has no credibility on this issue. His view will not change, regardless of what the science says. Does he care if stem cell research really offers a chance to cure diseases that today are untreatable?

So both of these stories show how difficult it is simply to report a biomedical story and explain its implications. The mammography story is especially complex, and the recommendations are much more nuanced than most people realize. Screening is costly, and the benefits are not so clear, especially given the tremendous anxiety that false positives cause. For example, a new study out of the University of Toronto found that for every additional breast cancer found through mammography, there were 55 false positives. This is a complicated issue, and all these politically-motivated voices only muddy the waters. The frequency of screening for different age groups is a debate worth having, if only politicians wouldn't co-opt it in order to push their own agendas.

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