Cost-effectiveness analysis of anastrozole vs tamoxifen in adjuvant therapy for early stage breast cancer in the United Kingdom: the 5-year completed treatment analysis of the ATAC (‘Arimidex’, Tamoxifen alone or in combination) trial

Abstract

Results from the completed treatment analysis of the ATAC (Arimidex, Tamoxifen alone or in combination) trial indicated that anastrozole was significantly superior to tamoxifen in terms of efficacy and safety in the adjuvant treatment of postmenopausal women with hormone receptor-positive (HR+) early breast cancer. On the basis of these results, this study estimated the cost-effectiveness of anastrozole vs tamoxifen, from the perspective of the UK National Health Service (NHS). A Markov model was developed using the 5-year completed treatment analysis from the ATAC trial (ISRCTN18233230), as well as data obtained from published literature and expert opinion. Resource utilisation data and associated costs (2003–4 UK£) were compiled from standard sources and expert opinion. Utility scores for a number of health states were obtained from a cross-sectional study of 26 representative patients using the standard gamble technique. The utility scores were then inserted into the model to obtain cost per quality adjusted life-year (QALY) gained. Costs and benefits were discounted at recommended annual rates of the UK Treasury (3.5%). Modelled for 25 years, anastrozole, relative to generic tamoxifen, was estimated to result in 0.244 QALYs gained per patient at an additional cost of £4315 per patient). The estimated incremental cost-effectiveness of anastrozole compared with tamoxifen was £17 656 per QALY gained. There was a greater than 90% probability that the cost-effectiveness of anastrozole was below £30 000 per QALY gained and of the order of 65% that it was below £20 000 per QALY gained. The results were robust to all parameters tested in sensitivity analysis. Compared with commonly accepted thresholds, anastrozole is a cost-effective alternative to generic tamoxifen in adjuvant treatment of postmenopausal women with HR+ early breast cancer from the UK NHS perspective.

Comparing the cost of adjuvant anastrozole with the benefits of managing less patients with relapsed breast cancer

“…This was estimated using a Markov Model and fitting Weibull Curves to the analysis of the ATAC trial (68 months data) [6]. This methodology required a key assumption that the benefit of anastrozole would carry over to 5 years following the end of treatment, which was later verified in the ATAC trial (100 months data) publication [1].…”

“…Health economic analyses of anastrozole have been conducted in the past [6], but all estimate the cost of a relapse using predictive modelling, questionnaires or interviews with clinicians [2,3,[7][8][9]]. An independent United Kingdom (UK) trial, now 6 years old, estimated hospital costs of relapsed breast cancer by sending questionnaires to UK oncologists, and estimated a cost of £12,500 per patient [10,11].…”

Cost-Effectiveness Analysis of Adjuvant Hormonal Treatments for Women with Postmenopausal Hormone-Receptor Positive Early Breast Cancer in the Korean Context

“…We estimated the utility values by pooling the data from the studies of the UK and US, which investigated preferences for the disease states associated with breast cancer. (41,42) …”

A Canadian Economic Analysis of U.S. Oncology Adjuvant Trial 9735

“…One sensitivity analysis used estimates reported by Mansel et al 25 (who reported lower decrements for local and distant recurrence) to explore the utility decrement associated with recurrence; a second used estimates reported by Locker et al 26 (who reported higher estimates for local and distant recurrence). Another sensitivity analysis assumed a utility score of 0.79 for disease-free patients surviving beyond 7 years.…”