Compliance with oral antiestrogens utilizing a bubble pack.

Abstract

132 Background: Adherence to endocrine therapy in breast cancer has been a long recognized problem despite efficacy to these drugs. Most of our knowledge of noncompliance has been largely observational and retrospective. Although multifactorial, extremes of age and race are risk factors for noncompliance. This report is an interim analysis of a well-designed study prospectively measuring compliance rates of “bubble” packaging of oral anti-estrogens Methods: A total of 88 patients were enrolled between August 2012 and April 2014. Out of 88 patients, 1 declined participation and 1 was deemed ineligible based on metastatic disease. Of the remaining 86, 53 continued participation and were included in this analysis. Demographic and clinical data were collected prospectively including age, race, insurance, duration of therapy, stage, and comorbidities. Duration of therapy was divided into 3 cohorts: early (less than 12 months), middle ( 12-36 months,) or late (37-60 months.) Comorbidities were defined as none, moderate (1-3) or significant (>3.) All patients received anti-estrogens in a “bubble”pack. All used bubble packs and missed dose diaries were returned at follow up appointments for review. Results: The majority of patients were white (77%)) and stage I/II (74%.) The overall compliance rate was 97%; however only 61% of enrolled patients were continued in the analysis. None of the variables examined race, age, insurance status and/ or stage had an impact on compliance. Only duration of therapy had a marginal effect on compliance (p value = 0.06.) The late cohort was least likely to be compliant at 89.53%, although only represented 9% of the included patients. Conclusions: The compliance rate of bubble packaging is higher than expected however should be interpreted with caution given the 39% withdrawal. Interestingly there was no difference in compliance rate among race, insurance status or age which contradicts our current knowledge on high risk groups. However duration of therapy did have a negative impact on compliance and may become increasingly important as duration of anti-estrogen therapy extends. However given the small number of patient in this cohort this will need to be confirmed at final analysis with larger involvement within this group. Clinical trial information: NCT01694225.