Abstract PO5-09-12: Unraveling the Intricacies of Racial Disparities in Breast Cancer in Brazil
Authors: da Silva Jesse Lopes , De Melo Andreia Cristina , Rodrigues Mariana Espirito Santo , de Albuquerque Lucas Zanetti , Thuler Luiz Claudio Santos 
Published: May 2024

Abstract Background: Over the past three decades, numerous countries have experienced a substantial decrease in breast cancer (BC) fatality, attributed to heightened consciousness, widened and earlier screening, and enhanced therapeutic interventions. However, these advancements have not eradicated the disparity in BC treatment across different racial and ethnic groups. In Brazil, the causes of these disparities are diverse and intricate, resembling health inequalities among ethnic communities observed in other countries. This study aimed to investigate the trends in BC incidence and mortality rates in Brazil, considering clinicopathological and sociodemographic variations, and placing particular emphasis on the severity of racial disparity concerning race/skin color. Patients and methods: Incidence trends for women with BC were analyzed using data from 13 Brazilian Population-Based Cancer Registries covering the period 2010-2015. Crude incidence ratios (CIRs) and the annual average percent change (AAPC) were calculated. Clinical and sociodemographic information from 348 Hospital-Based Cancer Registries spanning from 2000 to 2019 was also utilized. Meanwhile, mortality data for the years 2000-2020 were obtained from the National Mortality Information System. Racial and skin color data were collected through a self-declaration process, following the classification proposed by the Brazilian Institute of Geography and Statistics, which included categories such as white, black, and brown/mixed race. In the analysis, black and brown/mixed race categories were combined as black. Yellow and indigenous categories were excluded. Statistical significance was defined as a p-value less than 0.05. To determine clinically relevant differences, a threshold of more than 5% disparity in proportional values was used as an arbitrary criterion. Results: Between 2010 and 2015, a total of 70,896 newly diagnosed cases of BC were recorded. Mean CIRs were 83.9/100,000 for the overall population, 101.3/100,000 for white women, and 59.7/100,000 for black women. Neither the group of white women (AAPC -1.7; 95% CI: -7.9 to 4.9; p = 0.506) nor the group of black women (AAPC -0.4; 95% CI: -5.0 to 4.5; p = 0.831) exhibited any significant changes in the incidence rate. Black women predominantly originated from underdeveloped regions (56.4%, p &lt; 0.001), were referred by the public healthcare system in Brazil (79.0%, p &lt; 0.001), had ≤ 8 years of schooling (68.7%, p &lt; 0.001), were unmarried (50.9%, p&lt; 0.001), reported alcohol consumption (20.9%, p &lt; 0.001), and were diagnosed with advanced stage disease (60.1%, p &lt; 0.001). The escalation in mortality rates among black women exhibited a notable difference, amounting to 3.8 times the increase observed among white women (AAPC + 2.3; 95% CI: 2.1 to 2.5; p &lt; 0.001) (AAPC + 0.6; 95% CI: 0.5 to 0.7; p &lt; 0.001). Conclusion: Despite the lower incidence of BC in black women compared to their white counterparts, there is a concerning rise in BC-related mortality rates among black women. This group exhibits a significantly unfavorable sociodemographic and clinicopathological profile. These results highlight the pressing need to address the multifaceted factors contributing to these disparities, encompassing socioeconomic disparities and unequal healthcare access. Keywords: Breast cancer; racial disparities; incidence; mortality.

Citation Format: Jesse Lopes da Silva, Andreia Cristina De Melo, Mariana Espirito Santo Rodrigues, Lucas Zanetti de Albuquerque, Luiz Claudio Santos Thuler. Unraveling the Intricacies of Racial Disparities in Breast Cancer in Brazil [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-09-12.