title: Anthracycline regimen adherence in older patients with early breast cancer.
abstract: BACKGROUND
  Rates of anthracycline adherence in breast cancer (BC) patients are unknown, but noncompletion of chemotherapy is associated with worse outcomes.
  
  
  METHODS
  Using the Surveillance, Epidemiology, and End Results-Medicare database, we obtained demographics, comorbidities, tumor characteristics, and treatment and hospitalization data from stage I-III BC patients diagnosed at age ≥66 years in 1996-2005 treated with surgery who had anthracycline claims. We compared variables between patients with claims for less than four cycles, considered nonadherent cases, and those with claims for four or more cycles using logistic regression analyses.
  
  
  RESULTS
  The sample included 7,399 patients, of whom 1,222 (16.5%) were nonadherent cases. Two hundred forty-three (3.3%) patients had one claim, 298 (4.0%) had two claims, and 681 (9.2%) had three claims. The multivariate regression model showed statistically significant associations between nonadherence and older age, black race, unmarried status, diagnosis before the year 2001, and hospitalizations.
  
  
  CONCLUSIONS
  Eighty-three percent of older patients with early-stage BC completed at least four cycles of an anthracycline-based chemotherapy regimen. We identified a subset of patients with a higher likelihood of not adhering to the course of treatment. Further research is warranted to develop interventions to enhance adherence.
authors.affiliation: Department of Hematology and Oncology, TheUniversity of Texas MD Anderson Cancer Center, Houston, Texas, USA.
authors.forename: Carlos H
authors.initials: CH
authors.lastname: Barcenas
authors.forename: Ning
authors.initials: N
authors.lastname: Zhang
authors.forename: Hui
authors.initials: H
authors.lastname: Zhao
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Duan
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Buchholz
authors.forename: Gabriel N
authors.initials: GN
authors.lastname: Hortobagyi
authors.forename: Sharon H
authors.initials: SH
authors.lastname: Giordano
mesh_terms: D001741:Black or African American; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D018943:Anthracyclines / Q000627:therapeutic use*; D000903:Antibiotics, Antineoplastic / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy / Q000453:epidemiology* / Q000473:pathology; D005260:Female; D006760:Hospitalization; D006801:Humans; D008297:Male; D006278:Medicare; D055118:Medication Adherence; D009367:Neoplasm Staging; D012189:Retrospective Studies; D015996:Survival Rate; D014481:United States / Q000453:epidemiology
chemical_list: D018943:Anthracyclines; D000903:Antibiotics, Antineoplastic