Study Questions Net Benefits of Mammogram Screenings

Published August 21, 2015

Mammography screenings may not reduce the number of deaths from breast cancer and could even lead to an increase in unnecessary treatments, according to a study published in the Journal of the American Medical Association (JAMA) Internal Medicine.

In the JAMA study, researchers found a positive correlation between the extent of breast cancer screening and breast cancer incidence, but not with breast cancer deaths.

The new research contradicts conventional wisdom that mammograms reduce breast cancer deaths by 20 to 25 percent. The researchers suggest the reduction is closer to 10 percent, and they cite a problem of “widespread over-diagnoses” of breast cancer in American women.

Politics Matter

Mammograms cost around $100 each and are covered under most health insurance plans. In the United States, mammogram screenings for breast cancer cost $8 billion annually.

Independent health care analyst Greg Scandlen says annual mammograms starting at age 40 may harm some of the women they are meant to help, all while wasting billions of dollars.

“Mammogram coverage for most of the population is a political, rather than a medical, decision,” Scandlen said.

Medicare spends $1 billion annually on breast cancer screening, according to a study published in February 2013 in JAMA Internal Medicine.

For most of the population, mammograms are unnecessary and often harmful, Scandlen says.

“They lead to false positives, unnecessary biopsies, and enormous anxieties among healthy women,” said Scandlen. “This is true of many screening procedures for the general population. It is terribly inefficient to screen huge numbers of low-risk people. Mammography should be targeted towards women with known risk factors.”

On average, false-positive mammograms—test results that indicate a woman has breast cancer when she actually doesn’t—cost the nation $4 billion annually, according to research from the journal Health Affairs.

Tests Are Frequently Inaccurate

Dr. Jane Orient, executive director of the Association of American Physicians and Surgeons, underscores how frequently mammograms are inaccurate in low-risk populations.

“A 2005 study showed that if 1,000 women age 40–50 are screened, one of eight cancers will be missed, and 91 percent of the 77 positive tests are false,” Orient said.

Orient says early detection does not necessarily mean a cancer will be cured.

“It could be early detection does not prolong life, but only the length of time one lives with the diagnosis of cancer,” said Orient.

Danni Ondraskova ([email protected]) writes from Chicago, Illinois.

Internet Info

Charles Harding, et al., “Breast Cancer Screening, Incidence, and Mortality Across US Counties,” JAMA Internal Medicine, July 6, 2015:

Walter Krämer and Gerd Gigerenzer, “How to Confuse with Statistics or: The Use and Misuse of Conditional Probabilities,” Statistical Science, Vol. 20, No. 3, 223–230, Institute of Mathematical Statistics, November 2005:

Cary P. Gross, et al., “The Cost of Breast Cancer Screening in the Medicare Population,” JAMA Internal Medicine, Vol. 173, No. 3, February 11, 2013:

Mei-Sing Ong and Kenneth D. Mandl, “National Expenditure For False-Positive Mammograms And Breast Cancer Overdiagnoses Estimated At $4 Billion A Year,” Health Affairs, Vol. 34, No. 4, April 2015: