Trust the Science of Mammography

The following post was contributed by Jay Baker, MD, chair of the ACR Communications Committee of the Commission on Breast Imaging.

092412_baker001

In a recent commentary published on Medscape (1), Dr. Jha suggests that the debate over screening mammography should be about the financial costs per life saved rather than about the science of screening efficacy. He is both right and wrong.

Certainly society must consider the costs of any diagnostic test or treatment. But the costs considered must be more than the simple price tag charged to the insurance company or patient. There are also real financial costs to not screening for breast cancer. In one study, the cost of treating stage III disease (approximately $129,000 in the first year) was 50–100 percent greater than treating early stage breast cancer (approximately $60,000–$82,000) (2). Women without insurance bear those costs alone. The families of women who die unnecessarily of breast cancer lose out financially too. In a 2008 study, each family of a victim of breast cancer forfeits about $223,000 in the present value of lifetime earnings of the woman (3). Given the thousands of lives saved annually due to screening mammography, the costs of not screening, both in terms of lives and dollars, must be considered.

Unfortunately, Dr. Jha fails to consider that the debate over screening mammography is also heavily influenced by getting the science right. In fact, his commentary provides several examples of the dangers of using flawed information. For example, Dr. Jha reports that the American Cancer Society (ACS) advises women to start screening at age 45. In fact, the ACS said that if women knew the statistics and understood the science, most would want to begin annual screening mammography starting at age 40, and the ACS gave this approach to screening a qualified recommendation (4).

Dr. Jha further shows how important it is to understand the science of screening by quoting the long-discredited Canadian screening trials. Due to failed randomization in these trials, almost 80 percent of advanced breast cancers ended up in the screening cohort in year one of the trials, invalidating any subsequent outcomes from this study (5). Dr. Jha also quotes a recent article purporting to estimate the national expenditures for false-positive mammograms and breast cancer overdiagnoses (6). But the financial estimates from this paper are greatly inflated because the authors’ estimates of overdiagnosis rates aren’t supported by facts. The authors of that flawed study could not even determine whether screening led to the costs reported.

Dr. Jha states that determining the efficacy of screening “depends on how much you want to believe in mammograms.” But the beauty of science is that it is true whether or not you believe in it. Yes, we should consider all costs and benefits when deciding on the most appropriate regimen for breast cancer screening. But to have a rational discussion on this balance, we must get the science right so the numbers used have a foundation in fact, and we aren’t led astray by those, like Dr. Jha, who get the science wrong.

References

  1. Jha S 2016; The Mammogram Debate: How Much Should Be Spent to Save One Life?
  2. Blumen H, Fitch K, Polkus V. Comparison of Treatment Costs for Breast Cancer, by Tumor Stage and Type of Service. American Health & Drug Benefits. 2016;9(1):23-32.
  3. Bradley CJ, Yabroff KR, Dahman B, Feuer EJ, Mariotto A, Brown ML. Productivity costs of cancer mortality in the United States: 2000-2020. J Natl Cancer Inst. 2008;100(24):1763-70.
  4. Oeffinger KC, Fontham ET, Etzioni R, Herzig A, Michaelson JS, Shih YC, et al. Breast Cancer Screening for Women at Average Risk: 2015 Guideline Update From the American Cancer Society. JAMA. 2015;314(15):1599-614.
  5. Kopans DB, Feig SA. The Canadian National Breast Screening Study: a critical review. AJR Am J Roentgenol. 1993;161(4):755-60.
  6. Ong MS, Mandl KD. National expenditure for false-positive mammograms and breast cancer overdiagnoses estimated at $4 billion a year. Health Aff (Millwood). 2015;34(4):576-83.

 

Advertisements

Leave a Comment

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s