title: Association of hormone-related characteristics and breast cancer risk by estrogen receptor/progesterone receptor status in the shanghai breast cancer study.
abstract: Etiologic differences between subtypes of breast cancer defined by estrogen receptor (ER) and progesterone receptor (PR) status are not well understood. The authors evaluated associations of hormone-related factors with breast cancer subtypes in a population-based case-control study involving 1,409 ER-positive (ER+)/PR-positive (PR+) cases, 712 ER-negative (ER-)/PR-negative (PR-) cases, 301 ER+/PR- cases, 254 ER-/PR+ cases, and 3,474 controls aged 20-70 years in Shanghai, China (phase I, 1996-1998; phase II, 2002-2005). Polytomous logistic regression and Wald tests for heterogeneity across subtypes were conducted. Breast cancer risks associated with age at menarche, age at menopause, breastfeeding, age at first livebirth, waist-to-hip ratio, and oral contraceptive use did not differ by hormone receptor status. Among postmenopausal women, higher parity (≥2 children vs. 1) was associated with reduced risk (odds ratio (OR) = 0.69, 95% confidence interval (CI): 0.52, 0.91) and higher body mass index (BMI; weight (kg)/height (m)(2)) with increased risk (highest quartile: OR = 2.40, 95% CI: 1.65, 3.47) of the ER+/PR+ subtype but was unrelated to the ER-/PR- subtype (for parity, P(heterogeneity) = 0.02; for BMI, P(heterogeneity) < 0.01). Hormone replacement therapy (OR = 2.25, 95% CI: 1.40, 3.62) and alcohol consumption (OR = 1.59, 95% CI: 1.01, 2.51) appeared to be preferentially associated with the ER+/PR- subtype. These findings indicate that BMI, parity, hormone replacement therapy, and alcohol consumption may play different roles in subtypes of breast cancer. More research is needed to better understand the etiology of 2 relatively rare subtypes, ER+/PR- tumors and ER-/PR+ tumors.
authors.affiliation: Vanderbilt Epidemiology Center, Institute of Medicine and Public Health, Vanderbilt University Medical Center, 2525 West End Avenue, Suite 600, Nashville, TN 37203-1738, USA.
authors.forename: Ping-Ping
authors.initials: PP
authors.lastname: Bao
authors.forename: Xiao Ou
authors.initials: XO
authors.lastname: Shu
authors.forename: Yu-Tang
authors.initials: YT
authors.lastname: Gao
authors.forename: Ying
authors.initials: Y
authors.lastname: Zheng
authors.forename: Hui
authors.initials: H
authors.lastname: Cai
authors.forename: Sandra L
authors.initials: SL
authors.lastname: Deming
authors.forename: Zhi-Xian
authors.initials: ZX
authors.lastname: Ruan
authors.forename: Yinghao
authors.initials: Y
authors.lastname: Su
authors.forename: Kai
authors.initials: K
authors.lastname: Gu
authors.forename: Wei
authors.initials: W
authors.lastname: Lu
authors.forename: Wei
authors.initials: W
authors.lastname: Zheng
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D014408:Biomarkers, Tumor / Q000097:blood; D015992:Body Mass Index; D001943:Breast Neoplasms / Q000097:blood / Q000453:epidemiology* / Q000209:etiology; D002681:China / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D011960:Receptors, Estrogen / Q000097:blood*; D011980:Receptors, Progesterone / Q000097:blood*; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D014505:Urban Population; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone