American Journal of Epidemiology Advance Access originally published online on November 21, 2007
American Journal of Epidemiology 2008 167(4):447-456; doi:10.1093/aje/kwm322
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ORIGINAL CONTRIBUTIONS |
Population-based Case-Control Study of Diabetes and Breast Cancer Risk in Hispanic and Non-Hispanic White Women Living in US Southwestern States
1 Division of Cancer Prevention and Control, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL
2 Don and Erika Wallace Comprehensive Breast Program, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL
3 Health Research Center, University of Utah Health Sciences Center, Salt Lake City, UT
4 Department of Preventive Medicine and Biometrics, School of Medicine, University of Colorado, Denver, CO
5 Department of Epidemiology and Population Health, School of Public Health and Information Sciences, University of Louisville, Louisville, KY
Correspondence to Dr. Dana E. Rollison, Division of Cancer Prevention and Control, H. Lee Moffitt Cancer Center and Research Institute, 12902 Magnolia Drive, Tampa, FL 33612 (e-mail: dana.rollison{at}moffitt.org).
Received for publication June 5, 2007. Accepted for publication October 1, 2007.
Diabetes mellitus has been associated with breast cancer, although no studies appear to have adequately assessed the association in Hispanic women, a population with a high prevalence of diabetes. The authors investigated this association in a population-based case-control study of Hispanic and non-Hispanic White women living in the southwestern United States. Breast cancer cases diagnosed in 1999–2004 were identified through state cancer registries (1,526 non-Hispanic Whites, 798 Hispanics). Age- and ethnicity-matched controls (1,599 non-Hispanic Whites, 924 Hispanics) were selected from commercial mailing lists and driver's license and Social Security records. Diabetes history was assessed through interviewer-administered questionnaires. Odds ratios and 95% confidence intervals were calculated using logistic regression, adjusting for age, body mass index at age 15 years, and parity. Having any type of diabetes was not associated with breast cancer overall (odds ratio = 0.94, 95% confidence interval: 0.78, 1.12). Type 2 diabetes was observed among 19% of Hispanics and 9% of non-Hispanic Whites but was not associated with breast cancer in either group. Gestational diabetes was inversely associated with breast cancer in both ethnic groups, especially when first diagnosed at age 
35 years (odds ratio = 0.54, 95% confidence interval: 0.37, 0.79). In this study, diabetes was not associated with breast cancer overall, although the inverse association with gestational diabetes warrants further investigation.
breast neoplasms; case-control studies; diabetes, gestational; diabetes mellitus; diabetes mellitus, type 2; Hispanic Americans; insulin-like growth factor I; southwestern United States
Abbreviations: CI, confidence interval; ER, estrogen receptor; OR, odds ratio; PR, progesterone receptor