Examining the global occurrence and racial disparities in breast cancer is critical to our understanding of the disease etiology. Inflammatory breast cancer (IBC) is a rare and aggressive form of breast cancer, about which very little is known. Given the lack of comparative studies on breast cancer and inflammatory breast cancer on a global scale, this dissertation investigated trends in breast cancer in a population-based cancer registry in Gharbiah, Egypt. Furthermore, we utilized Surveillance, Epidemiology and End Results (SEER) registry data from California, Detroit and New Jersey to evaluate racial disparities in IBC, including among Arab Americans. Finally, this research focused on the lack of standardization in IBC diagnosis by comparing differing criteria for diagnosis to demonstrate the effect of differing criteria on estimating IBC occurrence.
The findings from this dissertation demonstrate significant increases in breast cancer incidence in Egypt from 1999-2008, particularly among women 50 years and older; estrogen receptor negative tumors were over represented. These observed trends add to our overall understanding of the etiology of breast cancer and can be used to inform clinicians and policy makers in this region of the world. Furthermore, our research demonstrates that IBC occurrence may be more common among certain minority groups in the United States, including Arab American women. With the significant lack of epidemiologic data on IBC, this study represents important progress toward our understanding of this disease. Finally, our study results suggest for the first time, that the incidence of IBC is likely to be underestimated in the U.S. SEER registry using the current SEER coding guidelines. Emphasis must be placed on the documentation of clinical and pathological characteristics of IBC in the medical record, so that analysis of putative IBC subtypes will be possible and we can further evaluate and come to a consensus on the definition of IBC to be utilized in future research.
This dissertation contributes to a better understanding of global heterogeneity in breast cancer and IBC and provides concrete scientific evidence in order to reduce the global burden of this disease.PHDEpidemiological ScienceUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/97974/1/kalamb_1.pd