Abstract 1172: Interrogating the molecular profile of breast cancer tumors in US Hispanics

Abstract Background: Breast cancer is the most commonly diagnosed cancer and the first leading of cancer related deaths among Hispanic women. The use of technologies, such as next generation sequencing (NGS), have led to the discovery of tumor biomarkers that are currently being used to guide personalized treatments to improve overall survival. Although several studies have characterized breast cancer tumors in Caucasian and European patients, a comprehensive genetic profiling of tumors from Puerto Rican Hispanics (PRH) has not been performed. In order to have a better understanding of the tumor biology of breast cancer among PRH, in this study we aimed to characterize the mutational landscape of breast cancer tumors from PRH and compare them to data available from other racial/ethnic groups from the mainland U.S.. Methods: A retrospective study design with data provided by CARIS Life Sciences was used to: 1) Estimate the prevalence of somatic mutations among breast cancer tumors from 189 Hispanics from PR (PRH) that underwent NGS testing from 2015 to 2020; and 2) Compare the mutation prevalence of PRH tumors with the breast cancer mutational profiles available through the TCGA Pan-Cancer Atlas Clinical Data (TCGA) and the AACR Project Genomics Evidence Neoplasia Information Exchange (GENIE), both databases can be accessed through the cBioPortal for Cancer Genomics. Descriptive statistics were performed to characterize the database. Results: Among the top mutated genes for breast cancer tumors among PRH were TP53 (65.9%, n=126), PIK3CA(22.7%, n=141), ARID1A (14.7%, n=68), NF1 (9.4%, n=64), RB1 (9.3%, n=108), PTEN (8.3%, n=133), GATA3 (7.3%, n=137), CDH1 (5.8%, n=139), MAP3K1 (5.6%, N=125), and BRCA2 (5.1%, n=136). The most frequent gene amplification for PRH were ZNF703 (15.0%, n=107), NSD3 (13.9%, n=108), ADGRA2 (12.2%, N=98), FGFR1 (11.2%, N=107), CCND1 (11.1%, n=108), MCL1 (10.2%, N=108), FGF3 (9.7%, N=93), NOTCH2 (9.4%, N=106), FGF4 (9.1%, N=99), FGF19 (8.8%, N=102), DDX5 (6.5%, N=108), EGFR (5.7%, N=106), and ERBB2 (5.6%, N=108). Conclusion: This is the first study to report the mutational profile of breast cancer tumors from PRH and to describe the difference in their mutational frequencies when compared other racial/ethnic populations using data from TCGA and GENIE databases. Understanding the somatic mutational landscape of breast cancer in PRH is crucial to guide research efforts in the development of new therapeutic modalities. Citation Format: Hilmaris Centeno-Girona, Ingrid Montes-Rodriguez, Harrison Torres-Pagan, Ceciliana Aldarondo-Hernandez, Ediel Rodriguez, Camila Rivera-Lynch, Noridza Rivera, Marcia Cruz-Correa. Interrogating the molecular profile of breast cancer tumors in US Hispanics [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1172.