Developing countries accounted for 45% of new breast cancer cases globally in 2009, and 57% in 2012, with these proportions projected to increase to 70% by 2030. Nigeria has experienced a three-fold increase in breast cancer incidence between 1973 and 2012, coinciding with an increase in the prevalence of so-called `diseases of affluence' including obesity, hypertension, and diabetes, a cluster of biochemical abnormalities that constitute Metabolic Syndrome (MetS). Recent studies in the US and Europe have shown a consistent positive association between MetS and breast cancer risk, suggesting that rising breast cancer rates in Nigeria may be a biological consequence of increasing rates of MetS. Once diagnosed with breast cancer, Nigerian women, similar to other women of African descent, are also more likely to present at younger ages, with highly aggressive, hormone-receptor negative tumors, associated with higher mortality. The reason for a higher prevalence of these tumor types in women of African descent is unclear. Epigenetic changes, through DNA methylation, histone modification and micro RNA changes are critical aspects of breast cancer tumorigenesis, and are influenced by both genetic background and environmental exposures. Multiple US studies have observed significant differences in DNA methylation levels of critical breast cancer genes between African- Americans and whites, including BRCA1 and BRCA2, CYP1A1, H-ras-1, and Cyclin D1. DNA methylation levels in critical breast cancer genes among Nigerian women have never been examined, and this may be the key to understanding racial differences in breast cancer phenotypes. Identification of race-specific epigenetic patterns could potentially be used as an intermediary marker of the association between exposures such as MetS and breast cancer incidence, or as prognostic markers for clinical management and therapeutic interventions. Using a sample of newly diagnosed breast cancer cases and age-matched healthy controls, this study aims to examine the association between MetS and breast cancer overall, and by sub-type in Nigeria. In addition, we plan to identify genome-wide DNA methylation differences between breast cancer tumor and adjacent normal tissue among women with and without MetS. These findings will provide critical information on the influence of MetS on breast cancer in Nigeria, and improve our understanding of the specific epigenetic changes that occur with breast cancer in Nigerian women; this is likely to be different from epigenetic changes observed among African American women with significantly different environmental exposures.

Public Health Relevance

Breast cancer rates in Nigeria are increasing very rapidly, and are predominantly of aggressive sub-types with poor prognosis. However, few studies have determined the factors associated with the increasing rates. This study provides critical information on the influence of metabolic syndrome as a risk factor for breast cancer in this population, and examines potential biological mechanisms through which it influences breast cancer.

Agency
National Institute of Health (NIH)
Institute
Fogarty International Center (FIC)
Type
Research Scientist Development Award - Research & Training (K01)
Project #
5K01TW010271-05
Application #
9775277
Study Section
International and Cooperative Projects - 1 Study Section (ICP1)
Program Officer
Michels, Kathleen M
Project Start
2016-09-28
Project End
2021-08-31
Budget Start
2019-09-01
Budget End
2020-08-31
Support Year
5
Fiscal Year
2019
Total Cost
Indirect Cost
Name
Duke University
Department
Type
DUNS #
044387793
City
Durham
State
NC
Country
United States
Zip Code
27705
Akinyemiju, Tomi; Moore, Justin Xavier; Pisu, Maria (2018) Mediating effects of cancer risk factors on the association between race and cancer incidence: analysis of the NIH-AARP Diet and Health Study. Ann Epidemiol 28:33-40.e2
Akinyemiju, Tomi; Do, Anh N; Patki, Amit et al. (2018) Epigenome-wide association study of metabolic syndrome in African-American adults. Clin Epigenetics 10:49
Akinyemiju, Tomi F; Demb, Joshua; Izano, Monika A et al. (2018) The association of early life socioeconomic position on breast cancer incidence and mortality: a systematic review. Int J Public Health 63:787-797
Akinyemiju, Tomi; Moore, Justin Xavier; Pisu, Maria et al. (2018) A Prospective Study of Obesity, Metabolic Health, and Cancer Mortality. Obesity (Silver Spring) 26:193-201
Akinyemiju, Tomi; Sakhuja, Swati; Waterbor, John et al. (2018) Racial/ethnic disparities in de novo metastases sites and survival outcomes for patients with primary breast, colorectal, and prostate cancer. Cancer Med 7:1183-1193
Akinyemiju, Tomi; Moore, Justin Xavier; Judd, Suzanne E et al. (2018) Pre-diagnostic biomarkers of metabolic dysregulation and cancer mortality. Oncotarget 9:16099-16109
Akinyemiju, Tomi; Sakhuja, Swati; Vin-Raviv, Neomi (2018) In-Hospital Mortality and Post-Surgical Complications Among Cancer Patients with Metabolic Syndrome. Obes Surg 28:683-692
Boakye, Jeffrey; Mensah, Danielle; Sakhuja, Swati et al. (2017) Socioeconomic Disparities in the Prevalence of Cardiometabolic Risk Factors in Ghanaian Women. Ann Glob Health 83:423-431
Global Burden of Disease Liver Cancer Collaboration; Akinyemiju, Tomi; Abera, Semaw et al. (2017) The Burden of Primary Liver Cancer and Underlying Etiologies From 1990 to 2015 at the Global, Regional, and National Level: Results From the Global Burden of Disease Study 2015. JAMA Oncol 3:1683-1691
Fowler, Mackenzie E; Akinyemiju, Tomi F (2017) Meta-analysis of the association between dietary inflammatory index (DII) and cancer outcomes. Int J Cancer 141:2215-2227

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