Purpose: This pilot study evaluated adherence to anti-estrogen therapy in women with hormone receptor-positive breast cancer utilizing bubble packaging.
Methods: This was a single-arm prospective investigational pilot study that enrolled 86 patients between August 2012 and April 2014. Descriptive statistics for patient age, race, insurance, stage, duration of treatment, and comorbidities were computed. All patients received routine prescriptions in a "bubble" pack or daily blister pack dispensed by one pharmacy. Participants were considered adherent if they had taken ≥ 80% of the dispensed drug. Disease-free survival (DFS) and overall survival (OS) data were obtained at 78 months.
Results: Fifty patients were included in the analysis. The overall adherence rate was 97%. None of the variables examined (race, age, insurance status, and stage) had an impact on adherence rate. Only duration of endocrine therapy had a marginal effect on adherence (p value = 0.06). The late cohort (duration of therapy 37-60 months) was least likely to be compliant at 89.53%. Our 5-year DFS was 94% and 5-year OS was 96%. There was no statistically significant difference in DFS and OS between patients with adherence rate > 90% and < 90%.
Conclusion: Adherence rate to bubble packaging was higher than that in historical studies. Although this is a single-arm pilot study, these data suggest bubble packaging of anti-estrogen may be a reasonable option to improve adherence in hormone receptor-positive breast cancer patients.
Keywords: Adherence; Anti-estrogen therapy; Breast cancer; Bubble packaging.