title: Early discontinuation and non-adherence to adjuvant hormonal therapy are associated with increased mortality in women with breast cancer.
abstract: Despite the benefit of adjuvant hormonal therapy (HT) on mortality among women with breast cancer (BC), many women are non-adherent with its use. We investigated the effects of early discontinuation and non-adherence to HT on mortality in women enrolled in Kaiser Permanente of Northern California (KPNC). We identified women diagnosed with hormone-sensitive stage I-III BC, 1996-2007, and used automated pharmacy records to identify prescriptions and dates of refill. We categorized patients as having discontinued HT early if 180 days elapsed from the prior prescription. For those who continued, we categorized patients as adherent if the medication possession ratio was ≥80%. We used Cox proportional hazards models to estimate the association between discontinuation and non-adherence with all-cause mortality. Among 8,769 women who filled at least one prescription for HT, 2,761 (31%) discontinued therapy. Of those who continued HT, 1,684 (28%) were non-adherent. During a median follow-up of 4.4 years, 813 women died. Estimated survival at 10 years was 80.7% for women who continued HT versus 73.6% for those who discontinued (P < 0.001). Of those who continued, survival at 10 years was 81.7 and 77.8% in women who adhered and non-adhered, respectively (P < 0.001). Adjusting for clinical and demographic variables, both early discontinuation (HR 1.26, 95% CI 1.09-1.46) and non-adherence (HR 1.49, 95% CI 1.23-1.81), among those who continued, were independent predictors of mortality. Both early discontinuation and non-adherence to HT were common and associated with increased mortality. Interventions to improve continuation of and adherence to HT may be critical to improve BC survival.
authors.affiliation: Department of Medicine and the Herbert Irving Comprehensive Cancer Center, College of Physicians and Surgeons, Columbia University Medical Center, 161 Fort Washington Avenue, 10-1068, New York, NY 10032, USA. dlh23@columbia.edu
authors.forename: Dawn L
authors.initials: DL
authors.lastname: Hershman
authors.forename: Theresa
authors.initials: T
authors.lastname: Shao
authors.forename: Lawrence H
authors.initials: LH
authors.lastname: Kushi
authors.forename: Donna
authors.initials: D
authors.lastname: Buono
authors.forename: Wei Yann
authors.initials: WY
authors.lastname: Tsai
authors.forename: Louis
authors.initials: L
authors.lastname: Fehrenbacher
authors.forename: Marilyn
authors.initials: M
authors.lastname: Kwan
authors.forename: Scarlett Lin
authors.initials: SL
authors.lastname: Gomez
authors.forename: Alfred I
authors.initials: AI
authors.lastname: Neugut
mesh_terms: D000368:Aged; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use*; D047072:Aromatase Inhibitors / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy / Q000401:mortality* / Q000473:pathology; D017024:Chemotherapy, Adjuvant; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008207:Lymphatic Metastasis; D008875:Middle Aged; D010349:Patient Compliance; D016016:Proportional Hazards Models; D013629:Tamoxifen / Q000627:therapeutic use*; D047368:Tumor Burden
chemical_list: D018931:Antineoplastic Agents, Hormonal; D047072:Aromatase Inhibitors; D013629:Tamoxifen
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