Mammography isn’t always a good idea
© 2015 Roy Benaroch, MD
Draft guidelines from the US Preventative Services Task Force (USPSTF) are concerning to some breast cancer advocates. The suggested guidelines no longer recommend routine mammography for women of average risk until age 50. For women from 40-49 years of age, the task force recommends an individualized assessment rather than screening all women.
These recommendations can have great economic weight. Under the Affordable Care Act, preventative services recommended by the USPSTF must be covered by health insurance with no cost-sharing. In other words, they’re not part of a deductible, and you’ll seem to get it for “free”. If these new draft recommendations stick, women in their 40’s will not have automatic free coverage for their yearly mammos (they could still get coverage if they’re in a special risk category.)
How’s this news going over in the breast cancer advocacy community? Not well. Full page ads ran last week, including on the back of the A section of the Washington Post, urging people sign a Change.org petition to get the US House of Representatives to step into the fight.
The petition starts:
Early detection saves lives. With one in eight women developing breast cancer during her lifetime, the earlier we can detect breast cancer, the better. After all, these are our mothers, daughters, grandmothers, wives, sisters, and friends, the people we care about most.
How can you argue with that? Where to these USPSTF numbskulls get off, letting more women die of cancer?
With the best intentions, the petitioners and many in the Breast Cancer advocacy community are getting it wrong. They say “Early detection saves lives”. But in this case, it’s not actually true.
Several good studies have shown that screening women in their 40s for breast cancer with mammography does not in fact save lives. In 2014, Canadian researchers did a randomized, controlled study– following over 50,000 women, half of whom were assigned to annual mammos, and half to no mammos from age 40-49. These women were then followed until age 60 to see how many died of breast cancer. In the mammo group, 134 died; in the non-mammo group, 122 died. That’s right, more women died who got mammos then women who did not (the difference was not statistically significant.) Screening mammos in this large, well designed clinical trial did not save lives.
Another study, from Great Britain, randomized about 160,000 women, starting at age 39. Again, those randomly assigned to get annual mammography were not less likely to die of breast cancer. It didn’t matter– whether or not yearly screening mammos were done, the death rates were the same. Screening mammos, again, didn’t save lives.
How could this be? Don’t we know that the earlier you detect cancer, the easier it is to treat? Unfortunately, medicine isn’t so simple. It turns out that many early breast cancers will regress (go away on their own), or grow so slowly that they never cause health problems. Of course, other breast cancers are aggressive and deadly– and women with those kinds of cancer benefit from treatment. But that has to be balanced against the genuine harm from therapy for breast cancer in many women who never needed treatment at all. And that therapy—it’s far from benign. Some women will die of complications caused by breast cancer therapy.
I’ve had two women very close to me killed by breast cancer, and I do not want to see more women suffer. But catchphrases — “Early screening saves lives”– are more to help fundraising than to guide policy. We need to figure out which women need earlier diagnosis and therapy, and how to best use mammography and other tools to help find women at-risk. But what we’re doing now, screening all women with mammos starting at 40, isn’t helping. It’s time to admit that, and move on.