Epidemiologia genética do câncer gástrico na população peruana

• Ano de defesa: 2012
• Autor(a) principal: Latife Pereira
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: Genética; Indios; Peru População; Estomago Cancer; Epidemiologia; Marcadores genéticos
• Link de acesso: http://hdl.handle.net/1843/BUBD-9BXFUT

Gastric cancer occurs with a high incidence in Peru and is the cancer that causes more number of deaths. This incidence is partially explained by differences in the prevalence of known risk factors. Genetic factors may also contribute to this difference in incidence. The Peruvian population received contribution of three ancestral populations: African, European and Native American. We used ancestry informative markers (AIMs) to estimate the ancestry of Peruvian gastric cancer cases and controls and assessed the association between gastric cancer and ancestry controlling 43 socioeconomic, nutritionals variables and symptoms. In order to synthesize the number of variables we used multivariate factor analysis. We genotyped 106 AIMs in 241 gastric cancer cases and 300 controls. Odds ratios (OR) for ancestry modeled as a continuous variable was estimated using logistic regression with age and individual scores from the three factors included as covariates. Higher Native American ancestry was associated with increased gastric cancer risk. The OR was 3.69 (p= 0.011), but when known risk factors were adjusted for, the association with Native American ancestry did not persist (OR= 1.28, p= 0.69). We also sequenced promoter regions of the IL8, IL8RA, IL8RB and PTGS2 genes in some Native American and case-control sampling (25, 61 and 58 individuals respectively) and after genotyped six polymorphisms: rs4073 (IL8), rs4674258 (IL8RB), rs689465 and rs689466 (PTGS2), rs10993994 (MSMB) and rs1219648 (FGFR2). The SNPs in the MSMB and FGFR2 were selected because they were associated with other types of cancer in genome wide association studies. The p values from the logistic regression analysis using the ancestry (continuous variable), the age and the individual scores from the factorial analysis as covariates were not significant (p>0.05). Further work would be interesting with a larger sampling and including more information about the tumor to determine if these variables could have influenced in our association study.