Poster Presentation COSA 2015 ASM

Patient Adherence to Aromatase Inhibitor Treatment in Early Stage Breast Cancer – local experience from Western Sydney hospitals (#191)

Sonia Cuan 1 , Bo Gao 2 3 , Rina Hui 2 3 , Richard Kefford 4 5
  1. Westmead Cancer Care Pharmacy, Westmead Hospital, Westmead, NSW, Australia
  2. Medical Oncology, Blacktown Hospital, Blacktown, NSW, Australia
  3. Medical Oncology, Westmead Hospital, Westmead, NSW, Australia
  4. Clinical Medicine, Melanoma Institute , Sydney, NSW, Australia
  5. Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, Australia

Background
Aromatase inhibitor (AI) is effective in various clinical setting for breast cancer, ranging from chemoprevention to treating in both adjuvant setting and metastatic disease. Each year Medicare Australia spends $50,000,000 on AI prescriptions, compared to $3,000,000 on tamoxifen prescriptions. The reported adherence rate to oral antineoplastic agents varied between 20 to 100%. Adherence to AI was evaluated to be suboptimal in America, but no local data is available in Australian. This study aimed to evaluate adherence rate and the factors affecting adherence in Western Sydney early breast cancer population.
Methods
The adherence rate was recalled by participants as the percentage of days they took AI. A Breast Cancer Hormonal Treatment Questionnaire was developed to evaluate factors affecting adherence. Non-adherence is identified if participants take AI in less than 80% of eligible days. Association between non-adherence and clinical characteristics were assessed using Pearson-2.
Results
The study recruited 82 early breast cancer women on AI between June 2012 and June 2014 from Westmead, Nepean and Norwest Private Hospitals. The median age was 62.5 years (range 38 to 83 years). The median time on AI was 4 years (range 1 to more than 5 years). 22.2% participants were non-adherent to AI treatment. Higher educational status (p=0.0088), good general health (p=0.0502) and higher stage disease (p=0.0451) were associated with non-adherence to AI treatment. The most common adverse reactions reported were muscles and joint aches (65.9%) which were higher than reported literature (25%). Regarding provision of information by healthcare professionals, only 28% of participant recalled receiving information before starting AI treatment.
Conclusions
Our study found non-adherence to AI is relatively common in Western Sydney early breast cancer population. We also identified potential factors associated with non-adherence. Due to the small sample size and limitation of patient self-recall, further validation in a large cohort is warranted.