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?