Study: Mammogram benefits overstated and harms downplayed

Research published in the Journal of the American Medical Association on the potential risks and benefits of mammography is the latest of several studies suggesting that mammograms may not be as beneficial as previously believed.

NBC Nightly News reported, “A team of researchers from Harvard has compiled more than 50 years of data about the effectiveness of mammograms” and “they’ve issued some controversial findings, with apologies for the confusion this may reignite.” NBC’s Chief Medical Editor, Dr. Nancy Snyderman, said that the “study … concluded the benefits of screening are often overstated and the harms downplayed.”

USA Today reports that the research indicates that “for every 10,000 women, mammograms probably save five lives of women in their 40s, 10 lives of women in their 50s and 42 lives of women in their 60s.” However, “breast cancer still kills 31 of those screened in their 40s, 62 screened in their 50s and 88 screened in their 60s.”

The Washington Post reports, however, that “the cumulative risk of a mammogram resulting in a false positive is about 61 percent for a 40- or 50-year-old woman who has annual mammograms for 10 years,” which may “result in needless surgery, chemotherapy or radiation.”

Here are some tables I developed from the data in the artilce. I found this informationm astonishing. See what you think:
POSSIBLE BENEFITS OF MAMMOGRAPHY BY AGE:
For every 1000 women having mammography Breast cancers detected by mammograms Breast cancer deaths, even having had mammograms Number of deaths averted (lives saved) by mammograms
Women in their 40s 19 3 0.5
Women in their 50s 30 6 1
Women in their 60s 44 9 4

POSSIBLE RISKS OF MAMMOGRAPHY BY AGE:

For every 1000 women having mammography Breast cancers detected by mammograms that would NEVER become clinically important 10 year risk of at least one “false positive” leading to unnecessary surgery or treatment Number of women with one or more unnecessary breast biopsies
Women in their 40s Up to10 613 (61%) 70
Women in their 50s Up to 14 613 (61%) 94
Women in their 60s Up to 19 497 (50%) 98

In an article titled “More Doubts About Mammograms’ Value Are Raised in Large Study,” the Wall Street Journal reports on the new study, and on the debate surrounding the benefits and risks of mammography. This article is worth your time to read.

The Boston Globe reports that in an accompanying editorial, Dr. Joann Elmore of Harborview Medical Center in Seattle, and Dr. Barnett Kramer of the National Cancer Institute, wrote, “For many physicians, conveying nuance and uncertainty may be difficult, especially when patients accept or expect clear answers.” Nevertheless, isn’t that exactly what we physicians should be trying to do?

The NPR “Shots” blog reports that “women age 75 and older really need to consider whether they should be having mammograms at all, a second study in JAMA reports.” The investigators “point out” that “there are no randomized controlled trials of mammography in women in that age group,” which means that it is impossible to determine “how much they might extend a woman’s life.”

NBC News points out on its website that “the debate about the value of mammograms has raged” for about five years now, since “the U.S. Preventive Services Task Force dramatically altered its recommendations, saying that women should get regular screenings starting at age 50, not 40, as was previously” recommended.

Based upon the information I’ve given you above, it looks like the USPSTF was more reasonable than many of their opponents. Furthermore, on its website, CBS News reports that another recent study “found regular mammograms didn’t necessarily lower risk for breast cancer death, even for women in their 50s, when the risk for developing the disease typically starts to increase.”

Enter your email to subscribe to Dr. Walt's blogs.

You have successfully subscribed to the newsletter

There was an error while trying to send your request. Please try again.

Dr. Walt Larimore will use the information you provide on this form to be in touch with you and to provide updates and marketing.