Evaluation of Patient Adherence to Anastrozole Therapy for Breast Cancer

PURPOSE: There are many reports that describe the effectiveness of aromatase inhibitors as endocrine therapy after breast cancer surgery. However, there are few detailed evaluations of patient adherence to anastrozole(ANA)therapy. Here, we evaluated the adherence to ANA therapy in postoperative patients with primary breast cancer. METHODS: We investigated 102 postoperative patients with primary breast cancer without distant metastasis, who received ANA at JCHO Kyusyu Hospital. We calculated the medication continuation rate and disease-free survival at 5 years from the initiation of medication. The reasons for medication discontinuation and alternative drug therapy after ANA therapy discontinuation were also investigated. Re- sults: The 5-year continuation rate of ANA treatment alone was 79%(81/102). The rate of all patients who continued ANA treatment, including 9 who changed to other drugs, was 88%(90/102). The most frequent ANA discontinuation reasons were progressive disease(8 cases), arthritis(5 cases), and nausea(3 cases). The disease-free survival rate was 92%(94/102), and the overall survival rate was 97%(99/102). CONCLUSION: ANA showed a high continuation rate. Adherence of ANA in postoperative patients with breast cancer was well maintained, even when the treatment was changed to other drugs due to adverse events.