Abstract C144: Poor survival in non-Hispanic Black HR+/HER2- and HR-/HER2+ breast cancer patients at an NCI-Designated Comprehensive Cancer Center

Abstract Introduction: In the US, 1 in 8 women face a breast cancer diagnosis within their lifetime. While this disease is pervasive, it does not affect all groups of women equally. Non-Hispanic Black (NHB) populations tend to have worse survival outcomes than Non-Hispanic White (NHW) and Hispanic (H) populations. Studying this disparity presents challenges, as it is influenced by many social and biological factors, including quality of cancer care. By comparing NHB, NHW, and H breast cancer patients at Moffitt Cancer Center (MCC), we can describe various factors related to disparate outcomes, while attenuating the effect of varying cancer care settings. Methods: Clinical data (collected from 1986-2018) and patient questionnaire data (collected from 2012-2020) were acquired from MCC databases. Patients were divided into NHW, NHB, and H groups based on their race and ethnicity. Family cancer history, hormonal contraception use, and HR/HER2 subtype were selected for analysis due to their relevance to breast cancer risk or prognosis. Descriptive statistics, chi-square tests, ANOVA, and Tukey tests were performed as appropriate. Results: On preliminary analysis, NHW patients most frequently report a history of cancer diagnosis in one or more first-degree relatives. This is found when considering all cancer types (p0.001) as well as specifically considering breast, ovarian, and uterine cancer (p=0.029). Patients also disclosed their hormonal contraception use, with 38% of NHW patients reporting an age at which they began using hormonal contraception compared to only 22% of both NHB and H patients (p0.001). Among those who have used hormonal contraception, there was no significant difference in age of use onset, or total years of use. Significant differences in HR+/HER2-(p0.001) and HR-/HER2- (p0.001) frequency were seen between groups. NHB women had the lowest frequency of HR+/HER2- cancers (57%), and the highest frequency of HR-/HER2- cancers (27%). HR-/HER2+ NHB patients displayed significantly worse overall survival relative to NHW (p0.001) and H (p=0.014) patients of the same subtype. HR+/HER2-NHB patients also have significantly worse overall survival relative to NHW (p=0.010) and H (p=0.010) patients of the same subtype. No significant difference in between-group overall survival is found for the HR-/HER2- and HR+/HER2+ patients. Conclusion: The cohorts in this study provide an opportunity to analyze characteristics and outcomes in breast cancer patients at an NCI-Designated Comprehensive Cancer Center. Higher rates of family cancer history in NHW women and higher rates of HR-/HER2- disease in NHB women align with the literature. NHW patients more frequently reported hormonal contraception use, while showing similarities to NHB and H groups in age and length of use. Despite comparable survival in two HR/HER2 subtypes, HR-/HER2+ and HR+/HER2- NHB women have significantly worse survival than NHW and H women. Further analyses of risk/prognostic factors and treatment regimens are needed to better understand this concerning survival finding. Citation Format: Abigail E. Lantz, Jiannong Li, Ryan F. Gebert, Dung-Tsa Chen, Edna R. Gordián, W. Douglas Cress. Poor survival in non-Hispanic Black HR+/HER2- and HR-/HER2+ breast cancer patients at an NCI-Designated Comprehensive Cancer Center abstract. In: Proceedings of the 17th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2024 Sep 21-24; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2024;33(9 Suppl):Abstract nr C144.