Ethnicity and breast cancer in the Women’s Health Initiative: A unifying concept for unfavorable outcome in African American women. R. T. Chlebowski, Z. Chen, T. Rohan, A. Aragaki, D. Lane, N. Dolan, E. Paskett, R. Patterson, A. Hubbell, R. Prentice, For the Women's Health Initiative Investigators; Harbor-UCLA Research & Education Institute, Torrance, CA; University of Arizona, Tucson, AZ; Albert Einstein College of Medicine, Bronx, NY; Fred Hutchinson Cancer Research Center, Seattle, WA; School of Medicine, SUNY, Stony Brook, NY; Northwestern University, Chicago, IL; Ohio State University, Columbus, OH; University of Calfornia, Irvine, Irvine, CA; , Seattle, WA Abstract: Background: The lower breast cancer incidence in minorities and higher breast cancer mortality in African Americans compared to Whites are largely unexplained. Therefore, relationships among ethnicity/race, breast cancer risk factors, and breast cancer were explored in an ethnically diverse cohort. Methods: Following comprehensive risk assessment, 156,570 postmenopausal WHI participants (129,037 White, 14,170 Black, 6,388 Hispanic, 4,114 Asians, 2,165 unknown and 696 American Indian) age 50 to 79 years were prospectively followed for breast cancer. Results: During 6.3 yrs median follow-up, 3938 invasive breast cancers were identified in 3455 Whites, 242 Blacks, 103 Hispanics, 88 Asians, 39 unknowns and 11 American Indians. Age-adjusted incidence rates for all minorities were lower compared to Whites. The ethnic differences approached unity and were largely explained by analysis models incorporating risk factor distribution and mammography use for Hispanics and Asians. However, for African Americans a significantly (p=0.02) lower incidence persisted (HR 0.82; 95% CI 0.69,0.96) after risk factor incorporation. African Americans had unfavorable cancers with combined poor/anaplastic grade plus ER negative cancers in 33% of cases vs 10% in Whites (OR 4.72, 95% CI 3.18,7.02). Mortality after breast cancer was greater in African Americans (HR 1.79; 95% CI 1.05,3.05). Obesity (Body Mass Index (BMI)>30kg/m2), seen in most (51%) African American women, was only a modest (p=0.16) predictor of unfavorable characteristics compared to African American ethnicity which was strongly (p<0.0001) associated with risk of poor/anaplastic grade plus ER negative cancers. Conclusions: Breast cancer risk factors have similar influence across ethnicity. In African American a high proportion of unfavorable cancers associated most strongly with ethnicity plausible explains the increased breast cancer mortality seen. Abstract No: 1008 Abstract # 673 ASCO, 2004 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.