MMC/VICC Partnership : Research
Obesity, Insulin Resistance, IGFs, and Breast Cancer Risk in African-Americans
CO-LEADERS
- Meharry Co-leader
Yong Cui, MD, MSPH -- Assistant Professor of Medicine
YCui@MMC.edu - Vanderbilt Co-leader
Wei Zheng, MD, PhD -- Professor of Medicine
Wei.Zheng@Vanderbilt.edu
Breast cancer is the most common malignancy among women and is the second leading cause of cancer-related deaths in the United States. African-American women, compared to their Caucasian counterparts, have a higher incidence of early-onset breast cancer, are more frequently diagnosed with aggressive breast cancer, and suffer a higher mortality rate. Only a limited number of epidemiological studies have been conducted over the past few decades to explore reasons behind these racial disparities, and the etiology of breast cancer in African-American women remains largely unknown. In this application, we propose to conduct a case-control study to test several important etiological hypotheses of breast cancer related to obesity and insulin resistance. These hypotheses are new and particularly relevant to the etiology of breast cancer in African Americans, as obesity and insulin resistance are substantially more prevalent in African Americans than in Caucasian Americans. Approximately 450 cases and 450 controls will be included in the investigation of these hypotheses, of which 300 cases and 300 controls will be recruited into this proposed study and the remaining 150 cases and 150 controls will be recruited as part of the ongoing NCI-funded Nashville Breast Health Study (R01CA100374). We propose to conduct telephone interviews to obtain dietary and other lifestyle information and collect exfoliated buccal cell samples to extract DNA for genotyping assays of polymorphisms in several major genes related to obesity (LEP, LEPR, RETN, APM1), insulin resistance (INS, INSR, IRS-1, IRS-2), and IGF-I effects (IGF-I, IGF-IR, and IGFBP-3). Cases newly diagnosed with primary breast cancer within a defined study period (2.5 years) and aged between 25 and 75 years will be identified through the population-based Tennessee Cancer Registry. Controls will be identified using a combination of DMV (the Tennessee Department of Motor Vehicles) files and a RDD (random digit dialing) protocol. They will be frequency matched to cases on age and residency county. This study, one of the first large, population-based case-control studies designed specifically to evaluate etiological factors for breast cancer in African-American women, will provide valuable information towards the understanding of the etiology of breast cancer in this underserved population.
