The Antidote

Counterspin for Health Care and Health News

Wednesday, March 28, 2007

Coverage: MRI screening recommendations for breast cancer

The New England Journal had an editorial today by Robert Smith, Director of Screening for the American Cancer Society, in which he presented the recommendation that women deemed to be at high risk of breast cancer should be screened by magnetic resonance imaging (MRI) directed at the breast. MRI is 10 times more sensitive than mammography - in other words, it picks up a lot more small tumors - but it's also less specific - i.e., there are more false positives. Furthermore, MRI screening is expensive, on the order of 10 times the cost of mammography, so the ACS is not recommending it for all women.

What's still missing is long-term, randomized studies that show a mortality benefit from MRI screening for women at high risk - or, indeed, any risk - of breast cancer.

I chose a convenience sample of articles on this topic in the three newspaper health sections I look at regularly, the Boston Globe, Washington Post, and New York Times. Each of the articles did a good job of presenting the pros and cons. The Times focused, in particular, on the cost issue. The writers' choice of quotes from experts added interesting nuance to the arguments. To wit, from the Times:
“Just to figure out who should have it will be the hardest thing,” Dr. Morris said. “A lot of that onus is put on the referring physician. A lot of women are going to think they’re high risk, and they’re not.”
The Post article got an unfortunate headline: "Annual Breast MRIs Urged For Women at Cancer Risk." I think you can safely say that most women are at some risk of breast cancer; the high-risk part really is crucial here. But it's probably not the writer's fault. Here's my favorite quote from the Post:
"You can find a lot of cancer, but that's not the same thing as helping people live longer or better," said Russell Harris of the University of North Carolina. "It's unclear how many women really will be helped and how many will be hurt by over-diagnosis and overtreatment."
Finally, the Globe gave the last word to a breast screening advocate:
Dr. Daniel Kopans, a radiologist at Massachusetts General Hospital, said studies of MRI's usefulness in the broader population are urgently needed.

"The real question . . . is whether we should be screening all women with MRI," said Kopans, noting that nobody knows how many of the 40,910 breast cancer deaths expected this year in the United States could be prevented with MRI. "What if MR screening could knock it down by 90 percent? Is that worth $800 apiece to do MR screening for everyone? These are very important questions, and somebody is going to have to bite the bullet and do a very large, expensive study" to find out.
Is that the real question? At least he's recommending a study, rather than recommending that we just screen everyone now... And 90%? Is that an evidence-based guess? Would any of my very smart friends out there like to take on Dr. Kopans' fondest hope?


At 4:07 PM, Blogger Roy M. Poses MD said...

Any ideas why MRI scans are still so expensive, given that the basic technology is well over 25 years old? In particular, why hasn't the availability of much more powerful computer hardware and software at much lower prices lead to a reduction in cost, given that MRI scans are heavily dependent on computer processing of the images?
See my related posts on the cost of CT scans here: and here:

At 1:20 PM, Anonymous Diora said...

Roy, don't you think that before we talk about cost we should at least consider if benefits would outweight the risks?

Going back to cost, you should factor in not just the cost of the test itself, but the cost of false positive evaluation and the cost of overtreatment. Until there is a test to determine which cancers will spread within one's lifetime, more accurate test=more overdiagnosis.

Orac has a good explanation for doctors as well as patients about why early detection isn't always a good thing.

At 2:10 PM, Anonymous Anonymous said...

I think the high cost of MRI scans has to do with its operating costs; the magnetic coils have to be maintained at a very low temperature via liquid helium, and the machinehas to be frequently calibrated.

Nevermind that it can cost 500k to construct a site and 1.5mil for a machine.


Post a Comment

Links to this post:

Create a Link

<< Home

Listed on BlogShares