A prospective clinical utility and pharmacoeconomic study of the impact of the 21-gene Recurrence Score® assay in oestrogen receptor positive node negative breast cancer

Purpose: The primary purpose of this study was to measure the impact of the 21-gene Recurrence Score (R) result on systemic treatment recommendations and to perform a prospective health economic analysis in stage I-II, node-negative, oestrogen receptor positive (ER+) breast cancer. Methods: Consenting patients with ER+ node negative invasive breast cancer and their treating medial oncologists were asked to complete questionnaires about treatment preferences, level of confidence in those preferences and a decisional conflict scale (patients only) after a discussion of their diagnosis and risk without knowledge of the Recurrence Score. At a subsequent visit, the assay result and final treatment recommendations were discussed prior to both parties completing a second set of questionnaires. A Markov health state transition model was constructed, simulating the costs and outcomes experienced by a hypothetical 'assay naive' population and an 'assay informed' population. Results: One hundred and fifty-six patients across two cancer centres were enrolled. Of the 150 for whom successful assay results were obtained, physicians changed their chemotherapy recommendations in 45 cases (30%; 95% confidence interval (CI) 22.8-38.0%); either to add (10%; 95% CI 5.7-16.0%) or omit (20%; 95% CI 13.9-27.3%) adjuvant chemotherapy. There was an overall significant improvement in physician confidence post-assay (p < 0.001). Patient decisional conflict also significantly decreased following the assay (p < 0.001). The simulation model found an incremental cost-effectiveness ratio of Canadian Dollars (CAD) $6630/quality-adjusted life years (QALY). Conclusion: Within the context of a publicly funded health care system, the Recurrence Score assay significantly affects adjuvant treatment recommendations and is cost effective in ER+ node negative breast cancer. (c) 2013 Published by Elsevier Ltd.