Original Article Lifetime recreational exercise activity and risk of breast carcinoma in situ Alpa V. Patel, Ph.D. 1 2, Michael F. Press, M.D. 3, Kathleen Meeske, Ph.D. 1, Eugenia E. Calle, Ph.D. 2, Leslie Bernstein, Ph.D. 1 * 1Department of Preventive Medicine, University of Southern California Keck School of Medicine, Los Angeles, California 2Department of Epidemiology and Surveillance Research, American Cancer Society, Atlanta, Georgia 3Department of Pathology, University of Southern California Keck School of Medicine, Los Angeles, California email: Leslie Bernstein (lbern@usc.edu) *Correspondence to Leslie Bernstein, Department of Preventive Medicine, University of Southern California, Los Angeles, CA 90033-9035 Fax: (323) 442-1992 Abstract BACKGROUND The incidence rates of breast carcinoma in situ (BCIS) have increased dramatically over the past two decades, primarily because of increased mammography screening. Ductal carcinoma in situ, which accounts for approximately 85% of BCIS and 10-20% of all breast carcinomas, is generally recognized as the final step in the progression to invasive disease. To the authors' knowledge, few studies have been conducted to date to evaluate BCIS risk factors. Because of its potential effects on circulating sex hormones, physical activity has been proposed as a modifiable risk factor for invasive breast carcinoma. However, the relation to BCIS risk is poorly understood. METHODS The authors analyzed data from a population-based case-control study conducted in Los Angeles County. Personal interviews were conducted with 567 white and black women (age range, 35-64 years) who had been newly diagnosed with BCIS between March 1, 1995 and May 31, 1998 and with 1026 control subjects, of whom 616 were screened within 2 years of identification. RESULTS After excluding unscreened control subjects (n = 410) and adjusting for potential confounding factors, the risk of BCIS was approximately 35% lower among women with any exercise activity compared with inactive women, although no significant trend was observed. The association between exercise activity and the risk of BCIS was modified by a family history of breast carcinoma. No reduction in risk was observed among women reporting a first-degree family history of breast carcinoma (homogeneity of trends P value = 0.02). CONCLUSIONS The findings of the current study suggest that exercise activity may modify the risk of BCIS, particularly among women without a family history of breast carcinoma. Cancer 2003. Volume 98, Issue 10 , Pages 2161 - 2169 Remember we are NOT Doctors and have NO medical training. This site is like an Encylopedia - there are many pages, many links on many topics. Support our work with any size DONATION - see left side of any page - for how to donate. You can help raise awareness of CAM.