title: Population stratification effect on cancer susceptibility in an admixed population from Brazilian Amazon.
abstract: OBJECTIVE
  Many efforts have been made to identify candidate genes involved in cancer susceptibility. The present study aimed to investigate the association between Arg194Trp (XRCC1), Ala222Val (MTHFR) and Arg521Lys (EGFR) polymorphisms (SNPs) and their susceptibility to gastric and breast carcinoma cancer in patients from Brazilian Amazon, controlling population structure interference.
  
  
  METHODS
  The SNPs were genotyped by TaqMan® SNP Genotyping Assays. Ancestry was estimated by analysis of a panel with 48 ancestry informative markers.
  
  
  RESULTS
  Logistic regression analysis showed an inverse association with a 10% increase in African and European ancestry and cancer risk (odds ratio (OR)=1.919 and 0.676, respectively). In a preliminary Chi-square analysis a positive association between Arg521Lys (EGFR) polymorphism and carcinoma susceptibility was found (p=0.037); however, when two different methodologies to control population structure bias were utilized, this association was lost (p=0.064 and p=0.256).
  
  
  CONCLUSIONS
  Genetic ancestry influence gastric and breast cancer risk and highlight the importance of population structure inference in association studies in highly admixed populations, such as those from Brazilian Amazon.
authors: Oncology Research Center, Federal University of Pará, Belém, Pará, Brazil Human Cytogenetics Laboratory, Federal University of Pará, Belém, Pará, Brazil.
authors: Priscilla Cristina Moura
authors: PC
authors: Vieira
authors: Oncology Research Center, Federal University of Pará, Belém, Pará, Brazil Human Cytogenetics Laboratory, Federal University of Pará, Belém, Pará, Brazil.
authors: Rommel Mario Rodríguez
authors: RM
authors: Burbano
authors: Oncology Research Center, Federal University of Pará, Belém, Pará, Brazil.
authors: Débora Christina Ricardo Oliveira
authors: DC
authors: Fernandes
authors: Oncology Research Center, Federal University of Pará, Belém, Pará, Brazil Human Cytogenetics Laboratory, Federal University of Pará, Belém, Pará, Brazil.
authors: Raquel Carvalho
authors: RC
authors: Montenegro
authors: Oncology Research Center, Federal University of Pará, Belém, Pará, Brazil.
authors: Sidney Emanuel Batista
authors: SE
authors: Dos Santos
authors: Oncology Research Center, Federal University of Pará, Belém, Pará, Brazil.
authors: Vinicius Albuquerque
authors: VA
authors: Sortica
authors: Oncology Research Center, Federal University of Pará, Belém, Pará, Brazil.
authors: Paulo Pimentel
authors: PP
authors: Assumpção
authors: Oncology Research Center, Federal University of Pará, Belém, Pará, Brazil.
authors: Ândrea Kely Campos
authors: ÂK
authors: Ribeiro-Dos-Santos
authors: Human Cytogenetics Laboratory, Federal University of Pará, Belém, Pará, Brazil.
authors: Antônio Alberto
authors: AA
authors: Carvalho
authors: Oncology Research Center, Federal University of Pará, Belém, Pará, Brazil npcsantos@yahoo.com.br.
authors: Ney Pereira Carneiro
authors: NP
authors: Dos Santos
mesh_terms: D044383:Black People; D001938:Brazil; D001943:Breast Neoplasms / Q000235:genetics* / Q000473:pathology; D004268:DNA-Binding Proteins / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D005828:Genetics, Population; D005838:Genotype; D006801:Humans; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide; D012307:Risk Factors; D013274:Stomach Neoplasms / Q000235:genetics* / Q000473:pathology; D044465:White People; D000076105:X-ray Repair Cross Complementing Protein 1
chemical_list: D004268:DNA-Binding Proteins; D000076105:X-ray Repair Cross Complementing Protein 1; C000619371:XRCC1 protein, human; C573423:MTHFR protein, human; D042965:Methylenetetrahydrofolate Reductase (NADPH2)
keywords: EGFR; MTHFR; XRCC1; ancestry; cancer; population stratification