September 23, 2010


Mammogram benefits more modest than doctors thought (Liz Szabo, 9/23/10, USA TODAY)

Nearly one year after the publication of controversial breast cancer screening guidelines by a government-appointed expert panel, a new study suggests benefits of mammograms may be more modest than previously estimated.

In a nationwide study in Norway, women in their 50s and 60s who got a mammogram every other year reduced their risk of dying from breast cancer by 10%, compared with those who didn't get the exams, according to a study in today's New England Journal of Medicine.

That's a much smaller benefit than estimated by even the U.S. Preventive Services Task Force, which says mammograms reduce breast cancer mortality by 15% to 23%. The task force's recommendations — advising that women may not need to begin screening until age 50 — ignited a fierce debate last November, in the midst of deliberations over health care reform. [...]

For 50-year-old women, mammograms may cut the 10-year risk of dying from breast cancer from 4.4 in 1,000 to 4 in 1,000, says H. Gilbert Welch of Dartmouth Medical School, who wrote an accompanying editorial.

Welch notes that most people are unaware of the risk of mammograms: They sometimes detect slow-growing tumors that don't pose a threat. Because doctors can't reliably tell which are life-threatening, however, they tend to treat all of them. Studies suggest that for every life saved by mammograms, five to 15 women may go through unnecessary treatment, he says.

CANCERING: Listening In On The Body's Proteomic Conversation: We make a mistake when we think of cancer as a noun. It is not something you have, it is something you do. Your body is probably cancering all the time. What keeps it under control is a conversation that is happening between your cells, and the language of that conversation is proteins. Proteomics will allow us to listen in on that conversation, and that will lead to much better way to treat cancer. (W. Daniel Hillis, Edge)

Hillis continues..."We misunderstand cancer by making it a noun. Instead of saying, "My house has water", we say, "My plumbing is leaking." Instead of saying, "I have cancer", we should say, "I am cancering." The truth of the matter is we're probably cancering all the time, and our body is checking it in various ways, so we're not cancering out of control. Probably every house has a few leaky faucets, but it doesn't matter much because there are processes that are mitigating that by draining the leaks. Cancer is probably something like that.

"In order to understand what's actually going on, we have to look at the level of the things that are actually happening, and that level is proteomics. Now that we can actually measure that conversation between the parts, we're going to start building up a model that's a cause-and-effect model: This signal causes this to happen, that causes that to happen. Maybe we will not understand to the level of the molecular mechanism but we can have a kind of cause-and-effect picture of the process. More like we do in sociology or economics."

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Posted by Orrin Judd at September 23, 2010 6:25 AM
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