title: Body mass index and risk of luminal, HER2-overexpressing, and triple negative breast cancer.
abstract: Triple negative (TN, tumors that do not express estrogen receptor (ER), progesterone receptor (PR), or human epidermal growth factor receptor 2 (HER2)) and HER2-overexpressing (H2E, ER-/HER2+) tumors are two particularly aggressive subtypes of breast cancer. There is a lack of knowledge regarding the etiologies of these cancers and in particular how anthropometric factors are related to risk. We conducted a population-based case-case study consisting of 2659 women aged 20-69 years diagnosed with invasive breast cancer from 2004 to 2012. Four case groups defined based on joint ER/PR/HER2 status were included: TN, H2E, luminal A (ER+/HER2-), and luminal B (ER+/HER2+). Polytomous logistic regression was used to estimate odds ratios (ORs) and associated 95 % confidence intervals (CIs) where luminal A patients served as the reference group. Obese premenopausal women [body mass index (BMI) ≥30 kg/m(2)] had an 82 % (95 % CI 1.32-2.51) increased risk of TN breast cancer compared to women whose BMI <25 kg/m(2), and those in the highest weight quartile (quartiles were categorized based on the distribution among luminal A patients) had a 79 % (95 % CI 1.23-2.64) increased risk of TN disease compared to those in the lowest quartile. Among postmenopausal women obesity was associated with reduced risks of both TN (OR = 0.74, 95 % CI 0.54-1.00) and H2E (OR = 0.47, 95 % CI 0.32-0.69) cancers. Our results suggest obesity has divergent impacts on risk of aggressive subtypes of breast cancer in premenopausal versus postmenopausal women, which may contribute to the higher incidence rates of TN cancers observed among younger African American and Hispanic women.
authors.affiliation: Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave N, Mail Stop M4-C308, P.O. Box 19024, Seattle, WA, 98109, USA. clu@fredhutch.org.
authors.forename: Lu
authors.initials: L
authors.lastname: Chen
authors.affiliation: Department of Internal Medicine, University of New Mexico and the University of New Mexico Comprehensive Cancer Center, Albuquerque, NM, USA.
authors.forename: Linda S
authors.initials: LS
authors.lastname: Cook
authors.affiliation: Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave N, Mail Stop M4-C308, P.O. Box 19024, Seattle, WA, 98109, USA.
authors.forename: Mei-Tzu C
authors.initials: MT
authors.lastname: Tang
authors.affiliation: Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave N, Mail Stop M4-C308, P.O. Box 19024, Seattle, WA, 98109, USA.|Division of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, WA, USA.
authors.forename: Peggy L
authors.initials: PL
authors.lastname: Porter
authors.affiliation: Department of Internal Medicine, University of New Mexico and the University of New Mexico Comprehensive Cancer Center, Albuquerque, NM, USA.
authors.forename: Deirdre A
authors.initials: DA
authors.lastname: Hill
authors.affiliation: Department of Internal Medicine, University of New Mexico and the University of New Mexico Comprehensive Cancer Center, Albuquerque, NM, USA.
authors.forename: Charles L
authors.initials: CL
authors.lastname: Wiggins
authors.affiliation: Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, 1100 Fairview Ave N, Mail Stop M4-C308, P.O. Box 19024, Seattle, WA, 98109, USA.
authors.forename: Christopher I
authors.initials: CI
authors.lastname: Li
mesh_terms: D000328:Adult; D001741:Black or African American; D000368:Aged; D015992:Body Mass Index; D001943:Breast Neoplasms / Q000453:epidemiology* / Q000209:etiology / Q000378:metabolism; D016022:Case-Control Studies; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006630:Hispanic or Latino; D006801:Humans; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D016017:Odds Ratio; D050177:Overweight / Q000150:complications* / Q000208:ethnology; D017697:Premenopause; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*; D011960:Receptors, Estrogen / Q000378:metabolism*; D011980:Receptors, Progesterone / Q000378:metabolism*; D064726:Triple Negative Breast Neoplasms / Q000453:epidemiology* / Q000209:etiology / Q000378:metabolism; D015854:Up-Regulation; D055815:Young Adult
chemical_list: D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; C508053:ERBB2 protein, human
keywords: BMI; Breast cancer; Obesity; Triple negative