Characterization of ancestry in patients with breast cancer in Brazil and its correlation with the molecular subtype and geographical origin.

• Grant number: 17/26304-7
• Support type: Regular Research Grants
• Duration: September 01, 2018 - February 28, 2021
• Field of knowledge: Health Sciences - Medicine - Surgery
• Principal researcher: René Aloisio da Costa Vieira
• Grantee: René Aloisio da Costa Vieira
• Home Institution: Hospital do Câncer de Barretos. Fundação Pio XII (FP). Barretos , SP, Brazil
• Assoc. researchers: Edenir Inêz Palmero ; Rui Manuel Vieira Reis ; Rui Pereira
• Associated scholarship(s): 18/16629-9 - Characterization of ancestry in patients with breast cancer in Brazil and its correlation with the molecular subtype and geographical origin, BP.TT

Abstract

Introduction: Breast cancer is the main type of cancer in women. In the light of current knowledge it is subdivided into molecular subtypes. The luminal molecular group is more frequent in white women, the triple negative group in African Americans, and the HER-2 group in the Hispanic population, in relation to the self-reported race in the United States. The advanced clinical stage is associated with non-white ethnicity, but socioeconomic and cultural factors are involved with possible selection biases. Studies on ancestry are limited, with discordant results against the markers of ancestry and self-reported race. In Brazil, despite high European descent in the population, luminal breast cancers are more frequent in the south-east and south, triple-negative and HER-2 more frequent in the north. The Brazilian population is mainly formed by European, African and Amerindian ancestry, but there are no studies evaluating the relationship between molecular subtype and ancestry in breast cancer. Methods: A retrospective study to be carried out in patients with invasive breast cancer from different Brazilian states, from a series of 5,557 patients, where 1000 patients will be selected, distributed equally in all Brazilian regions. Ancestry will be evaluated in relation to molecular subtypes. Comparisons between age, molecular subtype and Brazilian regions will be performed using the chi-square test. The differences in the regions will be compared through the Kruskal-Wallis test. For statistical analysis, the SPSS v.20.0 for Windows program (Chicago, IL) will be used. In front of ancestry will be extracted DNA from the paraffin. For ancestral analysis, the INDELs panel will be used, and the product will be evaluated through capillary electrophoresis. The results will be analyzed with the GeneMapper 4.0 software and the data will be evaluated in the Structure v.2.3.3 software for ancestral profile inference. Conclusion: This study will help us to answer questions related to age at diagnosis, stage of diagnosis, molecular subtype and ancestry, opening discussions on population genetic aspects. (AU)