Abstract C008: Descriptive analysis of Black/White disparities in triple-negative breast cancer for the United States—A population -based study from the United States Cancer Statistics database

Triple-negative breast cancer has been associated with a more aggressive histology, poorer prognosis and nonresponsiveness to hormone therapy. Due to the lack of therapeutic options for this cancer type, it is imperative that cancer research identify factors that drive disparities and focus on prevention. This study expands upon the literature by examining the outcome in population-setting rather than a sample, which can validate previous findings, by capturing the majority of the population. Using the United States Cancer Statistics database, we identified 1,151,724 cases of breast cancer from 2010-2014, with the triple-negative phenotype accounting for approximately 8.4% of all cases. The underlying distributions of age, race, and stage were statistically significantly different when we compared triple-negative breast cancer cases to all other breast cancer cases. Unadjusted and adjusted logistic regression results found that non-Hispanic black and Hispanic women had higher odds of diagnosis when compared to non-Hispanic white women, with non-Hispanic black women having over twice the odds of diagnosis. Additionally, those less than 50 years old had higher odds of diagnosis while those over 64 had lower odds, compared to age 50 to 64. Women younger than 40 had the highest odds of diagnosis, as compared to the referent group, with an odds ratio of approximately 1.8. Diagnosis at stage III and beyond conferred higher odds of diagnosis of triple-negative breast cancer. In adjusted analyses, these disparities persisted. A subset analysis was conducted on just non-Hispanic black and non-Hispanic white cases to explore the interaction of age, race and stage. This subset accounted for approximately 86% of the breast cancer population. Adjusted logistic regressions were run with age, race and stage as predictors of triple-negative breast cancer diagnosis. Interaction effects of age and stage by race were explored. Stage and race were statistically significant moderators of the relationship between age and diagnoses of triple-negative breast cancer. As age increased the odds of triple-negative diagnosis decreased; however, those diagnosed at late stage had higher odds of triple-negative breast cancer compared to those diagnosed in early stage. Additionally, non-Hispanic black women consistently had twice the probability of triple-negative diagnosis. This study shows that there is significant burden of disease in triple-negative breast cancer for women of color, specifically non-Hispanic black women, and younger women. Additional studies need to be conducted to determine what may be driving these disparities between race, age and stage.

Citation Format: Lia C. Scott. Descriptive analysis of Black/White disparities in triple-negative breast cancer for the United States—A population -based study from the United States Cancer Statistics database [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr C008.