Rerun: More on the overuse of mammography in elderly women

I’m taking a break from blogging this week so am rerunning some favorite posts from 2010. Please visit the original post to comment.

An oncologist friend spotted my blog post (Overuse of mammography in elderly women with cognitive impairment) and noticed that I’d been unable to access the full American Journal of Public Health article without paying for it. He shared his copy with me and pointed out that the research was funded by the National Institute of Aging (i.e., the taxpayer) and yet access is restricted to paid subscribers. (There is an antidote to this problem, called the Public Library of Science, which was co-founded by my high school lab partner.)

In any case a footnote in the article pointed me to an interesting 2001 article from the Journal of General Internal Medicine (Screening Mammography for Frail Older Women; What are the Burdens?) that is freely available. In this study, the authors followed the paths of 216 frail, elderly women who had undergone screening mammography. The results:

Thirty-eight women (18%) had abnormal mammograms requiring further work-up. Of these women, 6 refused work-up, 28 were found to have false-positive mammograms after further evaluation, 1 was diagnosed with ductal carcinoma in situ (DCIS), and 3 were diagnosed with local breast cancer. The woman diagnosed with DCIS and 1 woman diagnosed with breast cancer were classified as not having benefited, because screening identified clinically insignificant disease that would not have caused symptoms in the women’s lifetimes, since these women died of unrelated causes within 2 years of diagnosis. Therefore, 36 women (17%; 95% confidence interval [CI], 12 to 22) experienced burden from screening mammography (28 underwent work-up for false-positive mammograms, 6 refused further work-up of an abnormal mammogram, and 2 had clinically insignificant cancers identified and treated). Forty-two percent of these women had chart-documented pain or psychological distress as a result of screening. Two women (0.9%; 95% CI, 0 to 2) may have received benefit from screening mammography.

The article provides details of the four women diagnosed with breast cancer.  Two, who died within two years of detection, underwent some quite unpleasant and stressful testing and treatment. For example:

The second woman was an 89-year-old African-American woman with angina and dementia who was functionally dependent in 2 ADLs and who had a circular density in the left breast discovered by screening mammography. Serial mammograms were performed every 6 months for 2 years until it was felt that the lesion was slowly growing. An FNA revealed invasive ductal carcinoma. She underwent a modified radical mastectomy with no evidence of cancer in her axillary lymph nodes. She pulled off all the bandages the night after surgery, requiring restraints, and developed a seroma. She died 15 months later of a myocardial infarction.

The authors point out that –at least at the time of the article– some health care quality measures were based on the percentage of people over a certain age screened for cancer, with no regard for maximum age or individual circumstances that would make screening a bad idea.

The recent debate following the US Preventive Services Task Force recommendations on the age to begin routine mammography screening has focused heavily on the benefits of screening and the potential harm from discouraging screening. I’d like to see the debate broadened to include a frank discussion of the potential harm from too much screening. Excessive screening and associated harm to the frail elderly population is one aspect of that story.

December 30, 2010