One of the things that feels the weirdest about having done the same job, having been in the same specialty, for a longer and longer time is that you frequently feel, as the late, great Yogi Berra would have put it, déjà vu all over again. This is particularly true in science and medicine, where the same issues come up again and again and again, often with the same arguments on either side. Sometimes the same players are even involved. So it is with mammography recommendations. Indeed, I’m feeling déjà vu all over again right now, as I read headlines like “Women advised to get mammograms later, less often“, “American Cancer Society, in a Shift, Recommends Fewer Mammograms“, and “ACS: Breast cancer screening should begin at age 45“. What provoked these headlines was a major revision in the American Cancer Society’s recommendation for mammographic screening for breast cancer in women at average risk of the disease. In a seeming replay from 2009, when the United States Preventative Services Taskforce (USPSTF) sent shockwaves through the breast cancer world by recommending that most women not start mammography until age 50 and then only to have it done every two years instead of every year, the American Cancer Society (ACS) has now just similarly ratcheted back its recommendations for screening mammography, just not as much as the USPSTF did. The new recommendations were communicated in a special communication published by JAMA on Tuesday.
What changed regarding mammography recommendations
Before we get to the issues, how, specifically, did the ACS change its mammography recommendations? Before this change, the ACS basically recommended the same thing that most other American professional societies dealing with breast cancer did: yearly mammography starting at age 40 for the rest of a woman’s life. The new guidelines now recommend that women with an average risk of breast cancer should undergo regular screening mammography starting at age 45 years and continuing annually until age 54. From age 55 and older, the ACS recommends that women transition to every two years. (More details below.) As I Tweeted when I saw these recommendations, basically it appears that the ACS has more or less split the difference between the old recommendations and the USPSTF recommendations.
So why is the ACS changing its recommendations? And what does this say about the science and our values regarding cancer screening? If you’ve been reading this blog, you know that over the last several years there has been a steady drip, drip, drip of studies that range from highlighting the downside of widespread mammographic screening to downright questioning the value of mammography. That’s why I’ve been discussing rethinking screening for breast cancer since at least 2008. Basically, you can go back and read my old posts and, if you have a lot of time and are enough of a glutton for punishment to read them all, watch the evolution of my thinking about breast cancer screening over the last seven years.
Back in the day, I used to fully support breast cancer screening beginning at age 40 and proceeding yearly throughout. As I examined more and more of the evidence, I became less enthusiastic about screening so intensely and started to believe that starting at 40 was too young for most women. Indeed, I was probably the only breast cancer doctor at my cancer center in 2009 who supported the USPSTF recommendations when they were announced, which led to some—shall we say?—interesting discussions about what should be said to the press and what a press release our cancer center wanted to release ASAP should actually say. I also got myself into a little…trouble…for criticizing colleagues in radiology—not from my institution, I hasten to add!—for some rather blatant turf protection. Let’s just say that a prominent radiologist, one who’s achieved far more renown in his field than I ever have in mine, was most displeased with some of my commentary and let me know about it. I found this displeasure odd, given that I am most definitely not a nihilist with respect to mammography screening (and, make no mistake, there are quite a few of those out there these days). I’m just a lot more balanced and aware of its limitations than I used to be. On the other hand, I did call him out for some of his more obnoxious comments that implied that those who question mammography are cackling gleefully at the thought of more women dying of breast cancer. Interestingly, I don’t seem to get asked to contribute to such press releases that much anymore, but in fairness neither do most of the other breast cancer clinicians I work with; so I probably can’t blame it on my previous outspokenness.
What brought me to this point is an increasing understanding of the concepts of overdiagnosis and lead time bias, coupled with a string of studies that show more modest benefits (and, in one case, no benefit) from screening mammography. To be honest, the attack dog reaction by some mammography supporters to some of these negative studies also set my skeptical antennae a’twitchin’ as well.