In what is a short and fairly straightforward news release, we’re told by the American College of Radiology and American Society of Breast Imaging that all women age 40 and over should get an annual mammogram. Furthermore, readers are told that if they have any questions about the practice, they should consult their doctor.
But that’s about the extent of it. We’re never told how many lives could be saved by more regular screening, nor how those benefits stack up against growing concerns related to overdiagnosis and overtreatment. Nor is any evidence presented to back up the questionable assertion that “all women can benefit” from regular mammography.
Every year in the United States, breast cancer is diagnosed in about 224,000 women and kills about 41,000 women, per the CDC’s latest data. To detect and treat the disease as early as possible, clinicians perform more than 39 million mammograms a year, according to the FDA’s numbers. But mammography’s seemingly immutable benefit as an effective, life-saving tool has come under fire in recent years through the publication of large, longitudinal studies.
In 2014, for example, a British Medical Journal study of 89,000 Canadian women who were followed for 25 years found no benefit in the practice when it came to saving lives. It also found that 1 in 424 of those women received unnecessary cancer treatment. However, an American Cancer Society official told the New York Times in 2014 that the data showed a benefit for screenings in women in their 40s (i.e. a 15% reduction in breast cancer deaths).
Another study published by JAMA Oncology in 2015, which we examined in a recent blog post, focused on the most common diagnosis after mammography: ductal carcinoma in situ, or DCIS. (DCIS is a tissue anomaly contained within the ductwork of the breast, and is typically only visible in a high-resolution mammogram image.) The study looked at the medical records of 108,000 women diagnosed with DCIS and found that about 80% likely received unnecessary treatment; only black women and women diagnosed under the age of 35, an accompanying editorial concluded, should have received treatment.
For reasons that are still unclear, research continues to suggest that early screening is not as widely effective as was once believed — hence the push to clarify the benefits of mammography, as in this American College of Radiology news release that we review below.
The average cost of an annual mammogram is relatively easy to find, but this news release didn’t address it. The average out-of-pocket expense, per mammogram visit, is about $33. This is about 1/7th the cost of the full tab (approximately $266), according to a 2011 study in Journal of Women’s Health.
There aren’t any numbers on this, and it’s a crucial part of the sales pitch. The release says that screening regularly starting at age 40 “saves many more lives” than screening later or done less frequently. But how many more lives are we talking about? A quick look at at hyperlink in the release — which takes you to the ACR-produced advocacy website mammographysaveslives.org — and clicking “Are you confused?” takes you to a page that suggests mammography has reduced the U.S. breast cancer death rate by 30 percent. But that’s a relative risk reduction, and since the rate of breast cancer for women in their 40s is low, this figure may tend to inflate the size of the benefit for these women. We would have preferred to see a number describing the absolute reduction in breast cancer deaths. For example, according to a recent US Preventive Services Task Force evidence review, screening mammography prevents 4 deaths for every 10,000 women who are screened for at least 10 years compared with no screening.
Overdiagnosis and overtreatment aren’t discussed, but these are real and significant issues with mammography.
Without any quantification of how mammography can help a woman, and by sidestepping any mention of the two studies mentioned in the “Why This Matters” section (above), it’s difficult to argue this aspect of the release is Satisfactory. In fact, there is really no discussion of any of the evidence that supports screening mammography in this news release — it’s mainly composed of assertions that may or may not be supported by evidence. It’s impossible to tell since the evidence is never presented or discussed.
There are no gratuitous descriptions or inflammatory language in the release, and it encourages readers to discuss the issue with their doctors.
The Society of Breast Imaging and the American College of Radiology are clearly indicated.
A few options are mentioned, i.e. mammography screening only for high-risk groups, later-age screening, and less-than-annual mammograms. Other approaches that could have been discussed include regular physical exams of the breast by a clinician (without mammography) as well as breast self-exams.
Availability isn’t mentioned. But because getting a mammogram is relatively routine, we’ll mark this one “not applicable.”
Mammography has been around for decades, so what’s the news hook for the release? Apparently it’s the start of National Breast Cancer Awareness Month. Although that’s a pretty weak basis for putting out a news release, we’ll rule this Satisfactory as the release doesn’t pretend that there’s any actual news here..
A statement from Dr. Debra Monticciolov raised our eyebrows, especially given the surge in recent, high-quality evidence questioning the value of mammograms for some women: “All women age 40 and over can benefit from annual mammography.” In fact, it seems not every woman does benefit — for every woman whose life is saved, many more are overdiagnosed and overtreated. We think women should be encouraged to make an informed personal decision about screening mammography based on a clear understanding of the benefits and risks. This could include, in partnership with her doctor, a look at all known risk factors, including gender, age, race, family history, reproductive history, pregnancies, radiation exposure, previous abnormal breast biopsies, DES, HRT, alcohol use, obesity, physical activity, known genetic abnormalities, prior cancer classification, and other factors. Mammograms do not eliminate these risks.