Cost-Utility of Adjuvant Zoledronic Acid in Breast Cancer

The systemic treatments available for cancer management are often intended to either directly kill the cancer “seeds” in the body or alternatively affect the microenvironment “soil” where these cells grow. Patients with early-stage non-metastatic breast cancer often undergo a number of adjuvant systemic therapies including chemotherapy and endocrine treatments that could potentially kill the cancer seeds and reduce the risk of cancer recurrence. More recently, two clinical trials have suggested that repeated administration of an intravenous bone strengthening agent (Zoledronic Acid) could also reduce the risk of breast cancer relapse, perhaps by affecting the microenvironment, in post-menopausal women as well as pre-menopausal women undergoing ovarian function suppression therapy. Zoledronic acid however costs approximately $520 per infusion per patient, and was delivered for 6 up to 19 treatments over 3 to 5 year treatment course in these relevant trials. This study will employ a decision analysis framework / mathematical modeling that involve hypothetical patient cohorts to examine the upfront costs of Zoledronic Acid in the context of all relevant downstream events including lower relapse risk, improved patient survival, adverse events, quality of life, and costs. An assessment of the “value for money”, and potential budget impact, associated with adjuvant ZA in Canada could help the decision to incorporate this novel therapy in clinical practice and/or provide funding support by regulatory agencies. 1) To examine the CU associated with "adjuvant endocrine therapy plus ZA" vs. "adjuvant endocrine therapy without ZA" for patients with early-stage endocrine-sensitive breast cancer and LEL in CanadaThe cost-utility associated with adjuvant Zoledronic Acid will be examined within a state-transition model decision analysis framework to compute the incremental costs per quality-adjusted life years (QALY) gained associated with adjuvant Zoledronic Acid in patients with endocrine-responsive early-stage breast cancer with low circulating estrogen levels (LEL) over a life-time horizon (25 years).2) To compute the potential budget impact associated with adjuvant ZA for early-stage endocrine-sensitive breast cancer in Nova ScotiaThe annual budget impact of adjuvant Zoledronic Acid will be computed as the mathematical product of the expected net cost of Zoledronic Acid per patient, derived from the economic model, multiplied by the expected number of patients undergoing treatment in the year 2014.