Date of Award

8-7-2018

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Public Health

First Advisor

Lee Rivers Mobley, PhD

Second Advisor

Dora Il'yasova, PhD

Third Advisor

Tzy-Mey Kuo, PhD

Abstract

The objective of this study is to examine racial and geospatial disparities in triple-negative breast cancer diagnosis. Breast cancer, in general, carries an enormous public health burden. Triple-negative breast cancer has greater morbidity and mortality, presenting approximately 9% of all breast cancer diagnoses, in this study. This type of breast cancer has been significantly associated with younger age, African American race, later stage diagnosis, lower socioeconomic status and worse survival. The proposed study will be the first of its kind to use data from the United States Cancer Statistics database which includes combined cancer incidence data from the Centers for Disease Control and Prevention’s (CDC) National Program of Cancer Registries (NPCR) and the Surveillance, Epidemiology, and End Results (SEER) Program covering 99% of the population in comparison to 28% with SEER data alone. This study evaluates individual, social and physical environmental factors associated with disparate rates of diagnosis. Predictors of interest include person level-predictors (race, age, and stage of diagnosis), county-level predictors (residential segregation, social capital and socioeconomic climate), and state-level predictors (breast cancer screening mandates, state-level underinsured rates and state-specific restrictions on nurse practitioner or physician assistant scope of practice). Descriptive epidemiologic analysis allowed us to compare incidence of triple negative breast cancer across race and age groups at the individual level. This study confirmed that Non-Hispanic black women consistently had approximately twice the odds of diagnosis of triple negative breast cancer given breast cancer diagnosis, when compared to Non-Hispanic white women. Younger age and late stage diagnosis also conferred higher odds. Exploratory spatial data analysis was used to create descriptive maps and evaluate patterns of geospatial clustering and underlying community characteristics. This study found distinct patterns of breast cancer and triple negative breast cancer rates at the county level. It found 159 counties where breast cancer rates and triple negative breast cancer rates were concurrently high and 97 counties where breast cancer rates were low, but triple negative breast cancer rates were high. Spatial regression techniques demonstrated that residential segregation was consistently associated with both breast and triple negative breast cancer rates. Isolation was found to be detrimental while diversity was advantageous. Multilevel modeling allowed the exploration of predictors of triple-negative breast cancer diagnosis at the individual level. Consistently, race, age and late stage diagnosis conferred higher odds of diagnosis with triple negative breast cancer, given breast cancer diagnosis. Residential segregation measures were consistently associated, with isolation conferring higher odds and diversity conferring lower odds of diagnosis. The results of these studies potentially inform policy at actionable geographic levels and add valuable information to cancer health disparities research. Additionally, they provide insight that there is still a need to explore what factors may be driving racial and geospatial disparities in triple negative breast cancer in the United States.

Available for download on Friday, August 07, 2020

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