title: Breast Cancer Mortality in African-American and Non-Hispanic White Women by Molecular Subtype and Stage at Diagnosis: A Population-Based Study.
abstract: BACKGROUND
  Higher breast cancer mortality rates for African-American than non-Hispanic White women are well documented; however, it remains uncertain if this disparity occurs in disease subgroups defined by tumor molecular markers and stage at diagnosis. We examined racial differences in outcome according to subtype and stage in a diverse, population-based series of 103,498 patients.
  
  
  METHODS
  We obtained data for all invasive breast cancers diagnosed between January 1, 2005, and December 31, 2012, and followed through December 31, 2012, among 93,760 non-Hispanic White and 9,738 African-American women in California. Molecular subtypes were categorized according to tumor expression of hormone receptor (HR, based on estrogen and progesterone receptors) and human epidermal growth factor receptor 2 (HER2). Cox proportional hazards models were used to calculate relative hazard (RH) and 95% confidence intervals (CI) for breast cancer-specific mortality.
  
  
  RESULTS
  After adjustment for patient, tumor, and treatment characteristics, outcomes were comparable by race for stage I or IV cancer regardless of subtype, and HR(+)/HER2(+) or HR(-)/HER2(+) cancer regardless of stage. We found substantially higher hazards of breast cancer death among African-American women with stage II/III HR(+)/HER2(-) (RH, 1.31; 95% CI, 1.03-1.65; and RH, 1.39; 95% CI, 1.10-1.75, respectively) and stage III triple-negative cancers relative to Whites.
  
  
  CONCLUSIONS
  There are substantial racial/ethnic disparities among patients with stages II/III HR(+)/HER2(-) and stage III triple-negative breast cancers but not for other subtype and stage.
  
  
  CONCLUSIONS
  These data provide insights to assess barriers to targeted treatment (e.g., trastuzumab or endocrine therapy) of particular subtypes of breast cancer among African-American patients.
authors.affiliation: Cancer Prevention Institute of California, Fremont, California.
authors.forename: Li
authors.initials: L
authors.lastname: Tao
authors.affiliation: Cancer Prevention Institute of California, Fremont, California. Department of Health Research and Policy, Stanford University School of Medicine, Stanford, California.
authors.forename: Scarlett Lin
authors.initials: SL
authors.lastname: Gomez
authors.affiliation: Cancer Prevention Institute of California, Fremont, California. Department of Health Research and Policy, Stanford University School of Medicine, Stanford, California.
authors.forename: Theresa H M
authors.initials: TH
authors.lastname: Keegan
authors.affiliation: Department of Health Research and Policy, Stanford University School of Medicine, Stanford, California. Medicine, Stanford University School of Medicine, Stanford, California.
authors.forename: Allison W
authors.initials: AW
authors.lastname: Kurian
authors.affiliation: Cancer Prevention Institute of California, Fremont, California. Department of Health Research and Policy, Stanford University School of Medicine, Stanford, California. tina@cpic.org.
authors.forename: Christina A
authors.initials: CA
authors.lastname: Clarke
mesh_terms: D001741:Black or African American; D000367:Age Factors; D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis*; D001943:Breast Neoplasms / Q000175:diagnosis / Q000208:ethnology / Q000401:mortality*; D005260:Female; D006801:Humans; D008875:Middle Aged; D009367:Neoplasm Staging; D011159:Population Surveillance; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012959:Socioeconomic Factors; D015996:Survival Rate / Q000639:trends; D014481:United States / Q000453:epidemiology; D044465:White People
chemical_list: D014408:Biomarkers, Tumor