title: A nested case-control study of adjuvant hormonal therapy persistence and compliance, and early breast cancer recurrence in women with stage I-III breast cancer.
abstract: BACKGROUND
  Non-persistence and non-compliance are common in women prescribed hormonal therapy for breast cancer, but little is known about their influence on recurrence.
  
  
  METHODS
  A nested case-control study of associations between hormonal therapy non-persistence and non-compliance and the risk of early recurrence in women with stage I-III breast cancer was undertaken. Cases, defined as women with a breast cancer recurrence within 4 years of hormonal therapy initiation, were matched to controls (1 : 5) by tumour stage and age. Conditional logistic regression was used to examine associations between early recurrence and hormonal therapy non-persistence and non-compliance.
  
  
  RESULTS
  Ninety-four women with breast cancer recurrence were matched to 458 controls. Women who were non-persistent (≥ 180 days without hormonal therapy) had a significantly increased adjusted recurrence odds ratio (OR) of 2.88 (95%CI 1.11, 7.46) compared with persistent women. There was no significant association between low compliance (OR 1.30; 95% CI 0.74, 2.30) and breast cancer recurrence.
  
  
  CONCLUSIONS
  Hormonal therapy non-persistence is associated with a significantly higher risk of early recurrence in women with stage I-III oestrogen receptor (ER)-positive breast cancer. This finding is consistent with results from randomized studies of hormonal therapy treatment duration and suggests that interventions to target modifiable risk factors for non-persistence are required.
authors.affiliation: Department of Pharmacology and Therapeutics, Trinity College, University of Dublin, Dublin, Ireland.
authors.forename: T I
authors.initials: TI
authors.lastname: Barron
authors.forename: C
authors.initials: C
authors.lastname: Cahir
authors.forename: L
authors.initials: L
authors.lastname: Sharp
authors.forename: K
authors.initials: K
authors.lastname: Bennett
mesh_terms: D000328:Adult; D000368:Aged; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000473:pathology / Q000628:therapy; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D055118:Medication Adherence; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000473:pathology; D009367:Neoplasm Staging
chemical_list: D018931:Antineoplastic Agents, Hormonal