title: The association of soy food consumption with the risk of subtype of breast cancers defined by hormone receptor and HER2 status.
abstract: Soy food intake has previously been associated with reduced breast cancer risk. Epidemiological evidence for subgroups of breast cancer, particularly by menopausal and hormone receptor status, is less consistent. To evaluate the role of hormone receptor and menopausal status on the association between soy food intake and breast cancer risk, we measured usual soy food intake in adolescence and adulthood via food frequency questionnaire in 70,578 Chinese women, aged 40-70 years, recruited to the Shanghai Women's Health Study (1996-2000). After a median follow-up of 13.2 years (range: 0.01-15.0), 1,034 incident breast cancer cases were identified. Using Cox models, we found that adult soy intake was inversely associated with breast cancer risk [hazard ratio (HR) for fifth versus first quintile soy protein intake = 0.78; 95% confidence interval (CI):0.63-0.97]. The association was predominantly seen in premenopausal women (HR = 0.46; 95% CI:0.29-0.74). Analyses further stratified by hormone receptor status showed that adult soy intake was associated with significantly decreased risk of estrogen receptor (ER)+/progesterone receptor (PR)+ breast cancer in postmenopausal women (HR = 0.72; 95% CI:0.53-0.96) and decreased risk of ER-/PR- breast cancer in premenopausal women (HR = 0.46; 95% CI:0.22-0.97). The soy association did not vary by human epidermal growth factor-2 (HER2) status. Furthermore, we found that high soy intake during adulthood and adolescence was associated with reduced premenopausal breast cancer risk (HR = 0.53; 95% CI: 0.32-0.88; comparing third vs. first tertile) while high adulthood soy intake was associated with postmenopausal breast cancer only when adolescent intake was low (HR = 0.63; 95% CI: 0.43-0.91). Our study suggests that hormonal status, menopausal status and time window of exposure are important factors influencing the soy-breast cancer association.
authors.affiliation: Division of Epidemiology, Department of Medicine, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, TN.
authors.forename: Michelle L
authors.initials: ML
authors.lastname: Baglia
authors.affiliation: Division of Epidemiology, Department of Medicine, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, TN.
authors.forename: Wei
authors.initials: W
authors.lastname: Zheng
authors.affiliation: Department of Epidemiology, Shanghai Cancer Institute, Shanghai, People's Republic of China.
authors.forename: Honglan
authors.initials: H
authors.lastname: Li
authors.affiliation: Division of Epidemiology, Department of Medicine, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, TN.
authors.forename: Gong
authors.initials: G
authors.lastname: Yang
authors.affiliation: Department of Epidemiology, Shanghai Cancer Institute, Shanghai, People's Republic of China.
authors.forename: Jing
authors.initials: J
authors.lastname: Gao
authors.affiliation: Department of Epidemiology, Shanghai Cancer Institute, Shanghai, People's Republic of China.
authors.forename: Yu-Tang
authors.initials: YT
authors.lastname: Gao
authors.affiliation: Division of Epidemiology, Department of Medicine, Vanderbilt-Ingram Cancer Center, Vanderbilt University School of Medicine, Nashville, TN.
authors.forename: Xiao-Ou
authors.initials: XO
authors.lastname: Shu
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000453:epidemiology* / Q000209:etiology* / Q000378:metabolism; D004034:Diet Surveys; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008875:Middle Aged; D011159:Population Surveillance; D016016:Proportional Hazards Models; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D011960:Receptors, Estrogen / Q000378:metabolism; D011980:Receptors, Progesterone / Q000378:metabolism; D012306:Risk; D045730:Soy Foods
chemical_list: D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone
keywords: adolescence; breast cancer; hormone receptor status; menopausal status; soy