title: Attribution to Heterogeneous Risk Factors for Breast Cancer Subtypes Based on Hormone Receptor and Human Epidermal Growth Factor 2 Receptor Expression in Korea.
abstract: We conducted a heterogeneous risk assessment of breast cancer based on the hormone receptor (HR) and human epidermal growth factor receptor 2 (HER2) calculating the risks and population-based attributable fractions (PAFs) for modifiable and nonmodifiable factors.Using matched case-control study design from the Seoul Breast Cancer Study and the national prevalence of exposure, the risks and PAFs for modifiable and nonmodifiable factors were estimated for total breast cancers and subtypes.The attribution to modifiable factors was different for each subtype (luminal A, PAF = 61.4% [95% confidence interval, CI = 54.3%-69.8%]; luminal B, 21.4% [95% CI = 18.6-24.9%]; HER2-overexpression, 59.4% [95% CI = 47.8%-74.3%], and triple negative tumors [TNs], 27.1% [95% CI = 22.9%-32.4%)], and the attribution to the modifiable factors for the luminal A and HER2-overexpression subtypes was higher than that of the luminal B and TN subtypes (P heterogeneity  ≤  0.001). The contribution of modifiable reproductive factors to luminal A type in premenopausal women was higher than that of the other subtypes (18.2% for luminal A; 3.1%, 8.1%, and -3.1% for luminal B, HER2-overexpression, and TN subtypes, respectively; P heterogeneity  ≤  0.001). Physical activity had the highest impact preventing 32.6% of luminal A, 14.5% of luminal B, 38.0% of HER2-overexpression, and 26.9% of TN subtypes (P heterogeneity = 0.014). Total reproductive factors were also heterogeneously attributed to each breast cancer subtype (luminal A, 65.4%; luminal B, 24.1%; HER2-overexpression, 57.9%, and TN subtypes, -3.1%; P heterogeneity  ≤  0.001).Each pathological subtype of breast cancer by HRs and HER2 status may be associated with heterogeneous risk factors and their attributable risk, suggesting a different etiology. The luminal B and TN subtypes seemed to be less preventable despite intervention for alleged risk factors, even though physical activity had a high preventable potential against breast cancer.
authors.affiliation: From the Graduate School of Cancer Science and Policy, National Cancer Center (BP); Department of Preventive Medicine, Seoul National University College of Medicine (J-YC, HKS, CA, YH, JJ, JL, HK, K-YY, DK, SKP); Cancer Research Center (J-YC, CA, YH, JJ, JL, HK, DK, SKP); Department of Biomedical Science, Seoul National University College of Medicine, Seoul, Republic of Korea (J-YC, HKS, CA, YH, JJ, JL, HK, DK, SKP); Western Pacific Regional Office, World Health Organization, Manila, Philippines (H-RS); Department of Epidemiology and Health Promotion, Graduate School of Public Health, Yonsei University (SP); and Department of Surgery, Seoul National University Hospital and College of Medicine (WH-D-YN), Seoul, Korea.
authors.forename: Boyoung
authors.initials: B
authors.lastname: Park
authors.forename: Ji-Yeob
authors.initials: JY
authors.lastname: Choi
authors.forename: Ho Kyung
authors.initials: HK
authors.lastname: Sung
authors.forename: Choonghyun
authors.initials: C
authors.lastname: Ahn
authors.forename: Yunji
authors.initials: Y
authors.lastname: Hwang
authors.forename: Jieun
authors.initials: J
authors.lastname: Jang
authors.forename: Juyeon
authors.initials: J
authors.lastname: Lee
authors.forename: Heewon
authors.initials: H
authors.lastname: Kim
authors.forename: Hai-Rim
authors.initials: HR
authors.lastname: Shin
authors.forename: Sohee
authors.initials: S
authors.lastname: Park
authors.forename: Wonshik
authors.initials: W
authors.lastname: Han
authors.forename: Dong-Young
authors.initials: DY
authors.lastname: Noh
authors.forename: Keun-Young
authors.initials: KY
authors.lastname: Yoo
authors.forename: Daehee
authors.initials: D
authors.lastname: Kang
authors.forename: Sue K
authors.initials: SK
authors.lastname: Park
mesh_terms: D001943:Breast Neoplasms / Q000145:classification / Q000453:epidemiology* / Q000378:metabolism*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008875:Middle Aged; D016017:Odds Ratio; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000096:biosynthesis*; D011960:Receptors, Estrogen / Q000096:biosynthesis*; D011980:Receptors, Progesterone / Q000096:biosynthesis*; D056910:Republic of Korea; D018570:Risk Assessment; D012307:Risk Factors
chemical_list: D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; C508053:ERBB2 protein, human