Study questions benefits of community screening for breast cancer
(7 August 2005: VIDYYA MEDICAL NEWS SERVICE) -- During the past 20 years, results from randomized trials have led to the widespread adoption of screening mammography and clinical breast exams. However, a study in the July 20 Journal of the National Cancer Institute calls into question the mortality benefit of breast cancer screening as practiced in the real world, compared with the well-controlled situations of clinical trials.
Dr. Russell Harris of the University of North Carolina framed the question in an accompanying editorial: "To what extent is widespread screening in the United States in 2005 contributing to reducing breast cancer mortality?"
For the study, Dr. Joann Elmore and colleagues at the University of Washington reviewed the medical records of approximately 4,000 women from 6 health plans across 6 states. They identified 1,351 women who had died from breast cancer between 1983 and 1998, and 2,501 women, matched for age and risk factors, who had not been diagnosed with breast cancer.
The researchers found similar screening rates among the groups, but an advantage to screening was not clear. For example, 69.7 percent of the cancer patients aged 50-65 years with an average risk of developing the disease had gotten mammograms and/or breast examinations by a clinician in the past 3 years, compared with 69.2 percent of the cancer-free women of similar age and risk.
While the study results conclude that screening may have less impact on mortality in "real world" practice than it has proven to have in closely monitored clinical trials, the authors caution that their study is too small to verify that a modest reduction in mortality could be occurring in some subgroups. Additionally, they note, women who receive more than one screening within 3 years might have a greater benefit.
Return to Vidyya Medical News Service for 7 August 2005