Role of Genetic Ancestry in 1,002 Brazilian Colorectal Cancer Patients From Barretos Cancer Hospital

Author(s)

Duraes, Ronilson Oliveira ^{[1, 2]} ; Berardinelli, Gustavo Noriz ^[1] ; da Costa, Allini Mafra ^[3] ; Scapulatempo-Neto, Cristovam ^{[1, 4]} ; Pereira, Rui ^{[5, 6]} ; Oliveira, Marco Antonio ^[7] ; Guimaraes, Denise Peixoto ^{[1, 8]} ; Reis, Rui Manuel ^{[1, 9, 10]}

Affiliation

^[1] Barretos Canc Hosp, Mol Oncol Res Ctr, Barretos - Brazil

^[2] Barretos Canc Hosp, Dept Med Oncol, Barretos - Brazil

^[3] Barretos Canc Hosp, Canc Registry, Barretos - Brazil

^[4] Barretos Canc Hosp, Dept Pathol, Barretos - Brazil

^[5] Univ Porto, i3S, Porto - Portugal

^[6] Univ Porto, IPATIMUP Inst Mol Pathol & Immunol, Porto - Portugal

^[7] Barretos Canc Hosp, Nucleous Epidemiol & Stat, Barretos - Brazil

^[8] Barretos Canc Hosp, Endoscopy Dept, Barretos - Brazil

^[9] Univ Minho, Med Sch, Life & Hlth Sci Res Inst ICVS, Braga - Portugal

^[10] ICVS 3Bs PT Govt Associate Lab, Guimaraes - Portugal

• Document type: Journal article
• Source: FRONTIERS IN ONCOLOGY; v. 10, MAR 4 2020.
• Web of Science Citations: 0

Abstract

Background: Colorectal cancer (CRC) is the third most frequent and the second deadliest cancer worldwide. The ethnic structure of the population has been gaining prominence as a cancer player. The purpose of this study was to determine the genetic ancestry of Brazilian CRC patients. Moreover, we intended to interrogate its impact on patients' clinicopathological features. Methods: Retrospective observational cohort study with 1,002 patients with CRC admitted from 2000 to 2014 at Barretos Cancer Hospital. Following tumor DNA isolation, genetic ancestry was assessed using a specific panel of 46 ancestry informative markers. Survival rates were obtained by the Kaplan-Meier method, and the log-rank test was used to compare the survival curves. Multivariable Cox proportional regression models were used to estimate hazard ratios (HRs). Results: We observed considerable admixture in the genetic composition, with the following average proportions: European 74.2%, African 12.7%, Asian 6.5%, and Amerindian 6.6%. The multivariate analysis for cancer-specific survival showed that clinical stage, lymphovascular invasion, and the presence of recurrence were associated with an increased relative risk of death from cancer (p < 0.05). High African proportion was associated with younger age at diagnosis, while high Amerindian proportion was associated with the mucinous histological subtype. Conclusions: This represents the larger assessment of genetic ancestry in a population of Brazilian patients with CRC. Brazilian CRC patients exhibited similar clinicopathological features as described in Western countries. Impact: Genetic ancestry components corroborated the significant admixture, and importantly, patients with high African proportion develop cancer at a younger age. (AU)

• FAPESP's process: 18/22097-0 - Malignant neoplasms of the 18 cities of Barretos Regional Health District (RhD), Sao Paulo, Brazil: the importance of a population-based cancer registry
• Grantee: Allini Mafra da Costa
• Support Opportunities: Scholarships in Brazil - Post-Doctoral