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.
| Identifer | oai:union.ndltd.org:PITT/oai:PITTETD:etd-04142005-135825 |
| Date | 09 June 2005 |
| Creators | Okobia, Michael Nkwor |
| Contributors | Clareann H. Bunker, MPH, PhD, Victor G. Vogel, MD, MHS, Joseph M. Zmuda, PhD,, Candace M. Kammerer, PhD, Lewis H. Kuller, MD, DrPH |
| Publisher | University of Pittsburgh |
| Source Sets | University of Pittsburgh |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.library.pitt.edu/ETD/available/etd-04142005-135825/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to University of Pittsburgh or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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