title: Apolipoprotein E genetic polymorphism, serum lipoprotein levels and breast cancer risk: A case-control study.
abstract: The purpose of this study was to evaluate the association between apolipoprotein E (APOE) allelic frequency, serum lipoproteins and breast cancer (BC). We conducted a nested case-control study within a cohort including 47 cases and 165 controls. Polymerase chain reaction-restriction fragment length polymorphism analyses of the APOE polymorphism were performed. In general, participants with the genotype including alleles e2 and e3 tended to have lower serum triglycerides, total cholesterol and low-density lipoprotein cholesterol levels and higher high-density lipoprotein (HDL) cholesterol levels compared to participants homozygous for the e3 allele and participants heterozygous for the e3 and e4 alleles, respectively. BC patients exhibited higher mean levels of total serum cholesterol (P=0.070), dietary fat intake (P=0.020) and dietary cholesterol intake (P=0.017) compared to control subjects. The allelic distribution between the two groups revealed that the presence of the e2 allele was positively associated with the absence of BC, whereas the e4 allele was positively associated with the BC case group (P=0.019). The distribution of the APOE genotypes was not significantly different between cases and controls (P=0.172). The concomitant presence of the e2 and e4 alleles was positively associated with the absence of BC and e4/e4 homozygosity was positively associated with BC (P=0.021). Our findings suggested that APOE polymorphism plays an important role in the development of BC, particularly when associated with higher serum triglyceride levels.
authors.affiliation: Post-Graduate Program in Health Sciences, Cardiology and Cardiovascular Sciences, Universidade Federal do Rio Grande do Sul (UFRGS), Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, Brazil.
authors.forename: Gabriela Herrmann
authors.initials: GH
authors.lastname: Cibeira
authors.affiliation: Post-Graduate Program in Genetics and Molecular Biology, HCPA/UFRGS, Porto Alegre, Brazil ; Laboratory of Genomic Medicine, Experimental Research Center/Medical Genetics Service, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil.
authors.forename: Juliana
authors.initials: J
authors.lastname: Giacomazzi
authors.affiliation: Laboratory of Genomic Medicine, Experimental Research Center/Medical Genetics Service, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil.
authors.forename: Ernestina
authors.initials: E
authors.lastname: Aguiar
authors.affiliation: Laboratory of Genomic Medicine, Experimental Research Center/Medical Genetics Service, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil.
authors.forename: Silvana
authors.initials: S
authors.lastname: Schneider
authors.affiliation: Post-Graduate Program in Medicine: Medical Sciences, UFRGS/HCPA, Porto Alegre, Brazil.
authors.forename: Betina
authors.initials: B
authors.lastname: Ettrich
authors.affiliation: Post-Graduate Program in Medicine: Medical Sciences, UFRGS/HCPA, Porto Alegre, Brazil.
authors.forename: Caroline Isoppo
authors.initials: CI
authors.lastname: DE Souza
authors.affiliation: Post-Graduate Program in Epidemiology, Department of Statistics, Institute of Mathematics, UFRGS, Porto Alegre, Brazil.
authors.forename: Suzi
authors.initials: S
authors.lastname: Camey
authors.affiliation: Coorte Núcleo Mama Porto Alegre, Hospital Moinhos de Vento, Porto Alegre, Brazil.
authors.forename: Maira
authors.initials: M
authors.lastname: Caleffi
authors.affiliation: Hospital do Coração, São Paulo, Brazil.
authors.forename: Bernardete
authors.initials: B
authors.lastname: Weber
authors.affiliation: Laboratory of Genomic Medicine, Experimental Research Center/Medical Genetics Service, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil ; Post-Graduate Program in Medicine: Medical Sciences, UFRGS/HCPA, Porto Alegre, Brazil.
authors.forename: Patricia
authors.initials: P
authors.lastname: Ashton-Prolla
authors.affiliation: Post-Graduate Program in Health Sciences, Cardiology and Cardiovascular Sciences, Universidade Federal do Rio Grande do Sul (UFRGS), Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, Brazil ; Coorte Núcleo Mama Porto Alegre, Hospital Moinhos de Vento, Porto Alegre, Brazil.
authors.forename: Emilio Hideyuki
authors.initials: EH
authors.lastname: Moriguchi
keywords: apolipoprotein E; apolipoprotein E4; cardiovascular diseases; dyslipidemias; e4 allele