Women who exercised had a 35 percent lower risk of developing breast carcinoma in situ than did inactive women, according to a study in an upcoming issue of the journal Cancer released on the journal's Web site today. Alpa Patel, Ph.D., former doctoral student at the Keck School and now a researcher with the American Cancer Society, is the report's lead author.

Breast carcinoma in situ, or BCIS, consists of clusters of abnormal cells confined either to breast ducts (ductal carcinoma in situ) or lobules (lobular carcinoma in situ). Most BCIS cases are found through screening mammograms. Left untreated, some BCIS develop into invasive breast cancer.

"It's critical to know which factors are important at each stage of disease-because this knowledge may help you devise interventions or earlier means of detection. By identifying risk or protective factors for BCIS, we have the opportunity intervene a bit earlier in the cancer process," says Leslie Bernstein, Ph.D., professor of preventive medicine at the Keck School, AFLAC Chair in Cancer Research and the study's senior author.

Bernstein and other researchers have shown that regular physical activity reduces risk for invasive breast cancer, possibly by reducing levels of female hormones. But relationships between physical activity and BCIS risk are poorly understood.

For this latest study, epidemiologists studied more than a thousand women, either white or African-American, between ages 35 and 64 in Los Angeles County. They interviewed 567 women diagnosed with BCIS, and matched them to 616 BCIS-free women based on race and age group. All women had undergone a screening mammogram within two years of ide
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Contact: Jon Weiner
jonweine@usc.edu
323-442-2830
University of Southern California
6-Oct-2003