Women who did not undergo mammography accounted for 75% of breast cancer deaths

2009 ASCO Breast Cancer Symposium

The 20% of Massachusetts women who did not undergo regular screening mammograms accounted for almost three-quarters of breast cancer deaths, according to results of a study presented at the 2009 Breast Cancer Symposium in San Francisco.

“It seems to us, the most effective method of avoiding death from breast cancer is for women to participate in regular mammographic screening,” said Blake Cady, MD, emeritus professor of surgery at Harvard Medical School and Brown University Medical School. He presented the results during an oral abstract session Thursday afternoon.

Cady and colleagues conducted a retrospective population-based study on 6,997 Massachusetts women diagnosed with invasive breast cancer between 1990 and 1997. Survey results showed that about 80% of women in the state underwent regular mammography, defined as two or more mammograms at intervals of two years or less in women with no breast cancer symptoms.

There were 461 breast cancer-related deaths after a median of 12.5 years of follow-up. The researchers found that 74.8% of those deaths occurred in women who did not receive regular screening. Women who had never been screened accounted for 69.9% of deaths.

Cady said that, extrapolating these findings to the 192,000 women expected to be screened this year, he estimated that less than 5% of women regularly screened would die from breast cancer compared with 56% of women who do not undergo regular screening. – by Jason Harris

For more information:

Cady B. #24. Presented at: 2009 Breast Cancer Symposium; Oct. 8-10, 2009; San Francisco.

What Cady et al demonstrate in their analysis is that a higher proportion of breast cancer deaths occur in women without a recent mammogram. In fact, all the prognostic factors associated with tumor progression are more prevalent in the group that had not been screened than in the group that had recent screening.

– Robert Smith, MD

Director of Cancer Screening, American Cancer Society

We know from randomized trials that mammography leads to earlier detection of breast cancer and a reduction in breast cancer mortality. Dr. Cady's study looks at the benefit of mammography using a different approach. His study is a descriptive study that shows a high reduction in mortality for patients who had mammograms compared to those who did not undergo screening mammography, which is complementary to the results observed in the randomized trials. There could, however, be other factors that could contribute to the findings in Dr. Cady's study. I would conclude that the results of the Cady study support the importance of mammography in reducing deaths from breast cancer.

– Lori J. Pierce, MD

Professor of Radiation Oncology
Vice Provost for Academic and Faculty Affairs
Professor, Department of Radiation Oncology, University of Michigan

Follow HemOncToday.com on Twitter.