title: Breast cancer risk and erythrocyte compositions of n-3 highly unsaturated fatty acids in Japanese.
abstract: Dietary intake of fish rich in n-3 highly unsaturated fatty acids (HUFAs), such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), has been proposed to decrease cancer risk. In contrast to results from laboratory studies, however, protective effects for breast cancer have proved equivocal in epidemiological studies. In the present case-control study, we examined associations between breast cancer risk and fatty acid compositions in erythrocyte membranes as biomarkers for those intakes. Dietary information and blood samples were collected from 103 incident breast cancer cases and 309 non-cancer controls (matched by age and season) and erythrocyte fatty acids were measured using accelerated solvent extraction and gas-liquid chromatography. Dietary intake of n-3 HUFAs demonstrated a negative association with risk (the highest to the lowest tertile, odds ratio (OR), 0.51; 95% confidence interval (CI), 0.27-0.98; p(trend)<0.05), but there was no association with those of saturated fatty acids (SFAs) and meat. Moreover, risk was inversely associated with erythrocyte compositions of EPA (OR, 0.27; 95% CI, 0.14-0.53; p(trend)<0.0001), DHA (OR, 0.06; 95% CI, 0.02-0.16; p(trend)<0.0001) and n-3 HUFAs (OR, 0.11; 95% CI, 0.05-0.24; p(trend)<0.0001), and positively with that of SFAs (OR, 12.29; 95% CI, 4.94-30.57; p(trend)<0.0001) and the ratio of SFAs/n-3 HUFAs (OR, 14.65; 95% CI, 5.67-37.82; p(trend)<0.0001). In conclusion, we showed that erythrocyte compositions of specific fatty acids derived from fish intake, as biomarkers, are associated with lower risk of breast cancer, but further studies are needed to investigate mechanisms linked to the etiology.
authors.affiliation: Division of Epidemiology and Prevention, Aichi Cancer Center Research Institute, 1-1 Kanokoden, Chikusa-ku, Nagoya 464-8681, Japan. kkuriki@aichi-cc.jp
authors.forename: Kiyonori
authors.initials: K
authors.lastname: Kuriki
authors.forename: Kaoru
authors.initials: K
authors.lastname: Hirose
authors.forename: Kenji
authors.initials: K
authors.lastname: Wakai
authors.forename: Keitaro
authors.initials: K
authors.lastname: Matsuo
authors.forename: Hidemi
authors.initials: H
authors.lastname: Ito
authors.forename: Takeshi
authors.initials: T
authors.lastname: Suzuki
authors.forename: Akio
authors.initials: A
authors.lastname: Hiraki
authors.forename: Toshiko
authors.initials: T
authors.lastname: Saito
authors.forename: Hiroji
authors.initials: H
authors.lastname: Iwata
authors.forename: Masae
authors.initials: M
authors.lastname: Tatematsu
authors.forename: Kazuo
authors.initials: K
authors.lastname: Tajima
mesh_terms: D000328:Adult; D015992:Body Mass Index; D001943:Breast Neoplasms / Q000097:blood / Q000453:epidemiology*; D016022:Case-Control Studies; D004912:Erythrocytes / Q000737:chemistry*; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage / Q000032:analysis*; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008875:Middle Aged; D015999:Multivariate Analysis; D016017:Odds Ratio; D012307:Risk Factors
chemical_list: D015525:Fatty Acids, Omega-3