title: Associations between sociodemographic and clinicopathological factors and breast cancer subtypes in a population-based study.
abstract: OBJECTIVE
  This study examines the factors distinguishing breast cancer (BC) subtypes.
  
  
  METHODS
  We examined subtypes in 629 women with invasive BC, diagnosed from 2006 to 2012, and enrolled in an epidemiological study in New Jersey. Using molecular characteristics from pathology reports, BCs were categorized as luminal A, luminal B, non-luminal HER2-expressing, or triple-negative breast cancer (TNBC) subtypes. Multinomial logistic models (luminal A as referent) were used to describe BC subtype associations.
  
  
  RESULTS
  Women with luminal B tumors were more likely to be younger at diagnosis [odds ratio (OR) 1.8, 95% confidence interval (CI) 1.0-3.4] and to have higher-grade (OR 2.6, 95% CI 1.5-4.7), larger (OR 1.9, 95% CI 1.0-3.6), and Ki67-positive tumors (OR 2.1, 95% CI 1.1-4.0). Women with non-luminal HER2-expressing BCs were more likely to have higher-grade tumors (OR 14.5, 95% CI 5.3-39.7). Women with TNBCs were more likely to be African-American (OR 1.9, 95% CI 1.0-3.4) and to have higher-grade (OR 9.7, 95% CI 5.1-18.4), larger (OR 2.2, 95% CI 1.0-4.8), and Ki67-positive (OR 2.9, 95% CI 1.6-5.2) tumors. Notably, compared to the luminal A subtype, luminal B, non-luminal HER2-expressing, and triple-negative subtypes were more frequently self-detected; however, these associations were attenuated in multivariable models.
  
  
  CONCLUSIONS
  These findings suggest that some BC subtypes were associated with features denoting more aggressive phenotypes, namely higher grade, larger size, and Ki67 positivity, and possibly patient self-detection among some women. These findings highlight a need for enhanced screening, particularly among younger women, racial/ethnic minorities, and lower socioeconomic subgroups.
authors.affiliation: Department of Epidemiology, Rutgers School of Public Health, 683 Hoes Lane West, Room 211, Piscataway, NJ, 08854, USA. Adana.Llanos@Rutgers.edu.|Rutgers Cancer Institute of New Jersey, New Brunswick, NJ, USA. Adana.Llanos@Rutgers.edu.
authors.forename: Adana A M
authors.initials: AA
authors.lastname: Llanos
authors.affiliation: Department of Epidemiology, Rutgers School of Public Health, 683 Hoes Lane West, Room 211, Piscataway, NJ, 08854, USA.|Rutgers Cancer Institute of New Jersey, New Brunswick, NJ, USA.
authors.forename: Sheenu
authors.initials: S
authors.lastname: Chandwani
authors.affiliation: Department of Epidemiology, Rutgers School of Public Health, 683 Hoes Lane West, Room 211, Piscataway, NJ, 08854, USA.|Rutgers Cancer Institute of New Jersey, New Brunswick, NJ, USA.
authors.forename: Elisa V
authors.initials: EV
authors.lastname: Bandera
authors.affiliation: Rutgers Cancer Institute of New Jersey, New Brunswick, NJ, USA.|Division of Medical Oncology, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, USA.
authors.forename: Kim M
authors.initials: KM
authors.lastname: Hirshfield
authors.affiliation: Rutgers Cancer Institute of New Jersey, New Brunswick, NJ, USA.|Department of Biostatistics, Rutgers School of Public Health, Piscataway, NJ, USA.
authors.forename: Yong
authors.initials: Y
authors.lastname: Lin
authors.affiliation: Department of Cancer Prevention and Control, Roswell Park Cancer Institute, Buffalo, NY, USA.
authors.forename: Christine B
authors.initials: CB
authors.lastname: Ambrosone
authors.affiliation: Department of Epidemiology, Rutgers School of Public Health, 683 Hoes Lane West, Room 211, Piscataway, NJ, 08854, USA.|Rutgers Cancer Institute of New Jersey, New Brunswick, NJ, USA.
authors.forename: Kitaw
authors.initials: K
authors.lastname: Demissie
mesh_terms: D000328:Adult; D001741:Black or African American / Q000706:statistics & numerical data; D001943:Breast Neoplasms / Q000453:epidemiology / Q000473:pathology*; D005260:Female; D006801:Humans; D008875:Middle Aged; D009515:New Jersey; D016017:Odds Ratio; 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 / Q000473:pathology*
chemical_list: D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone
keywords: African-American women; Aggressive phenotypes; Breast cancer; Clinicopathological factors; Subtypes