title: Clinical and economic outcomes by first-line treatment among women with HR+/HER2- metastatic breast cancer in a large US health plan database.
abstract: Guidelines recommend that women with hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR+/HER2-) metastatic breast cancer (mBC) initiate hormonal therapy before chemotherapy. This study compared outcomes of women with mBC who received chemotherapy first vs hormonal therapy.
  
  
  
  A retrospective cohort study of women with mBC was conducted using a large US commercial health plan database between January 1, 2008-April 30, 2013. Subjects had evidence of a HR+/HER2- tumor sub-type in a cancer registry and use of chemotherapy or hormonal therapy in claims. Subjects were continuously enrolled for ≥6 months after metastasis and assigned to cohorts for receiving chemotherapy only or hormonal therapy only during first-line (CT-1L vs HT-1L). Adjusted incidence rates of clinically significant events were compared using a negative binomial model, and adjusted healthcare costs were compared using a generalized linear model.
  
  
  
  Three hundred and twenty-four women with HR+/HER2- mBC met the selection criteria; 179 (55%) received CT-1L and 145 (45%) received HT-1L. Mortality rates did not differ between cohorts (unadjusted incidence rate ratio (IRR) = 1.67, 95% CI = 0.82-3.46; adjusted IRR = 0.64, 95% CI = 0.32-1.27). Adjusted average total all-cause healthcare costs were $11 090 for women with CT-1L and $6743 for women with HT-1L (cost ratio =1.64, 95% CI =1.36-1.99).
  
  
  
  Observed use of first-line chemotherapy (>50%) was higher than expected given the HR + molecular profile of the tumors. Chemotherapy use during first-line did not appear to be associated with a survival benefit, but was associated with significantly higher costs compared with the use of hormonal therapy during first-line; however, this comparison is limited by demographic and baseline characteristic differences between the two cohorts. This study contributes to understanding real-world treatment patterns and the associated clinical and economic outcomes of using chemotherapy vs hormonal therapy as a first-line treatment option for the HR+/HER2- mBC population.
authors.affiliation: a Optum , Waltham , MA , USA ;
authors.forename: Tanya
authors.initials: T
authors.lastname: Burton
authors.affiliation: b Optum , Eden Prairie , MN , USA ;
authors.forename: Stacey DaCosta
authors.initials: SD
authors.lastname: Byfield
authors.affiliation: c Pfizer Inc , New York , NY , USA ;
authors.forename: Gregory L
authors.initials: GL
authors.lastname: Smith
authors.affiliation: c Pfizer Inc , New York , NY , USA ;
authors.forename: Giovanni
authors.initials: G
authors.lastname: Zanotti
authors.affiliation: c Pfizer Inc , New York , NY , USA ;
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Bell
authors.affiliation: c Pfizer Inc , New York , NY , USA ;
authors.forename: Julia J
authors.initials: JJ
authors.lastname: Perkins
authors.affiliation: c Pfizer Inc , New York , NY , USA ;
authors.forename: Ruslan
authors.initials: R
authors.lastname: Horblyuk
authors.affiliation: d HemeOnc Associates , Carlsbad , CA , USA.
authors.forename: April
authors.initials: A
authors.lastname: Teitelbaum
mesh_terms: D000328:Adult; D001943:Breast Neoplasms / Q000737:chemistry / Q000188:drug therapy* / Q000473:pathology; D015331:Cohort Studies; D016208:Databases, Factual; D005260:Female; D017048:Health Care Costs; D006801:Humans; D008875:Middle Aged; D009362:Neoplasm Metastasis; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000032:analysis*; D011960:Receptors, Estrogen / Q000032:analysis*; D012189:Retrospective Studies
chemical_list: D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; C508053:ERBB2 protein, human
keywords: Chemotherapy; Clinical and economic outcomes; HR+/HER2– sub-types; Metastatic breast cancer; Real-world data