Adherence to adjuvant therapy in post-menopausal breast cancer patients: a review

This review aimed to address the concept of adherence to adjuvant therapy in post-menopausal women. Thirteen studies were included in the review. Study quality was assessed using Critical Appraisal Skills Programme and CONSORT tools. Adherence to adjuvant medication was assessed using a variety of methods. Estimates of adherence rates to adjuvant therapies indicated that of the post-menopausal women prescribed adjuvant therapy, between 15% and 55% were adherent to tamoxifen from 1 to 5 years of follow-up, albeit two studies proposed adherence rates greater than 85%; these data may be flawed due to the methods of data collection. Between 31% and 73% of women were adherent to anastrozole, letrozole or exemestane from 1 year of treatment. These estimates of adherence are based on a variety of reported records including self-report. Current evidence on the assessment of adherence to adjuvant therapies in post-menopausal women indicate that the adherence rates of medication maybe suboptimal and therefore therapeutic efficacy is questionable and may increase the risk of cancer recurrence and reduce disease survival rates. Concerted research is needed to investigate adherence rates, examine patient health beliefs in the medication management of postmenopausal breast cancer patients and also develop new measures to assess adherence with medication.