Okobia, Michael Nkwor
(2005)
ESTROGENS, GENETIC POLYMORPHISMS AND BREAST CANCER RISK IN NIGERIAN WOMEN.
Doctoral Dissertation, University of Pittsburgh.
(Unpublished)
Abstract
Breast cancer is major cause of morbidity and mortality globally and the incidence appears to be rising faster in population groups that hitherto experience lower incidence. This case control study recruiting 250 women with breast cancer and 250 age-matched controls from four University Teaching Hospitals in Nigeria was designed to evaluate the risk factors for breast cancer in Nigerian women. Family history of breast cancer was associated with a 15-fold increased risk of breast cancer [Odd ratio (OR) = 14.99, 95% Confidence interval (CI), 1.98, 113.47]. Also, waist to hip ratio (OR = 2.10, 95% CI 1.44, 3.06), history of abortion (OR = 2.83, 95% CI 1.12, 7.19), increasing age at first childbirth (OR = 1.39 95% CI 1.11, 1.73) and higher level of education (OR = 1.31, 95% CI 1.07, 1.61) conferred increased risk of breast cancer. Increasing parity (OR = 0.87, 95% CI 0.77, 0.99) and increasing duration of breastfeeding (OR = 0.75, 95% CI 0.62, 0.91) conferred protection against breast cancer. In the final multivariate conditional logistic regression in all women, carrying at least one low-activity COMT (Met) allele was associated with a significant 43% reduced risk of breast cancer (OR = 0.57, 95% CI 0.36-0.91). While harboring the CYP1A1 M1 polymorphic variant was associated with non-significant reduced risk of breast cancer (OR = 0.79, 95% CI 0.48-1.29), the CYP1A1 M3 polymorphism conferred a non-significant 24% reduced risk of breast cancer (OR = 0.76, 95% CI 0.47-1.22). Results of this study have important public health implications; it has provided evidence for a role for reproductive and other variables in susceptibility to breast cancer in indigenous African women, thus contributing to the global epidemiologic literature on risk factors for breast cancer in populations of African ancestry. It has also provided data suggesting protection for breast cancer for women harboring the low-activity COMT (Met) allele of the codon 158 polymorphism of the COMT gene. In addition, the findings of this study will serve a useful resource tool in future research and policy decisions aimed at breast cancer control and prevention in these populations.
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Details
| Item Type: |
University of Pittsburgh ETD
|
| Status: |
Unpublished |
| Creators/Authors: |
|
| ETD Committee: |
| Title | Member | Email Address | Pitt Username | ORCID |
|---|
| Committee Chair | Bunker, Clareann H | | | | | Committee Member | Kammerer, Candace M | | | | | Committee Member | Zmuda, Joseph M | | | | | Committee Member | Kuller, Lewis H | | | | | Committee Member | Vogel, Victor G | | | |
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| Date: |
9 June 2005 |
| Date Type: |
Completion |
| Defense Date: |
6 April 2005 |
| Approval Date: |
9 June 2005 |
| Submission Date: |
14 April 2005 |
| Access Restriction: |
No restriction; Release the ETD for access worldwide immediately. |
| Institution: |
University of Pittsburgh |
| Schools and Programs: |
School of Public Health > Epidemiology |
| Degree: |
PhD - Doctor of Philosophy |
| Thesis Type: |
Doctoral Dissertation |
| Refereed: |
Yes |
| Uncontrolled Keywords: |
breast cancer; Estrogens; Nigeria; risk factors |
| Other ID: |
http://etd.library.pitt.edu/ETD/available/etd-04142005-135825/, etd-04142005-135825 |
| Date Deposited: |
10 Nov 2011 19:37 |
| Last Modified: |
15 Nov 2016 13:40 |
| URI: |
http://d-scholarship.pitt.edu/id/eprint/7141 |
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