Department of Pharmacy and Pharmacology, The Netherlands Cancer Institute and MC Slotervaart, Amsterdam, The Netherlands.
Division of Pharmacology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX, Amsterdam, The Netherlands.
Breast Cancer Res Treat. 2018 Nov;172(1):143-150. doi: 10.1007/s10549-018-4886-8. Epub 2018 Jul 13.
Breast cancer is the most common malignancy in women worldwide. Recurrence rates in breast cancer are considered to be dependent on the serum concentration of endoxifen, the active metabolite of tamoxifen. The goal of this study is to investigate the cost-effectiveness of periodically monitoring serum concentrations of endoxifen in adjuvant estrogen receptor alfa (ERα) positive breast cancer patients treated with tamoxifen in the Netherlands.
A Markov model with disease-free survival (DFS), recurrent disease (RD), and death states was constructed. The benefit of drug monitoring was modeled via a difference in the fraction of patients achieving adequate serum concentrations. Robustness of results to changes in model assumptions were tested through deterministic and probabilistic sensitivity analyses.
Monitoring of endoxifen added 0.0115 quality-adjusted life-years (QALYs) and saved € 1564 per patient in the base case scenario. Deterministic sensitivity analysis demonstrated a large effect on the incremental cost-effectiveness ratio (ICER) of the differences in costs and utilities between the DFS and RD states. Probabilistic sensitivity analysis showed that the probability of cost-effectiveness at a willingness to pay of € 0 per quality-adjusted life-year (QALY) was 89.8%.
Based on this model, monitoring of endoxifen in adjuvant ERα + breast cancer patients treated with tamoxifen is likely to add QALYs and save costs from a healthcare payer perspective. We advise clinicians to consider integrating serum endoxifen concentration monitoring into standard adjuvant tamoxifen treatment of ERα + breast cancer patients.
乳腺癌是全世界女性最常见的恶性肿瘤。乳腺癌的复发率被认为取决于他莫昔芬的活性代谢物(endoxifen)的血清浓度。本研究旨在探讨在荷兰，用他莫昔芬治疗雌激素受体α(ERα)阳性乳腺癌患者时，定期监测血清 endoxifen 浓度的成本效益。
构建了一个无病生存(DFS)、复发性疾病(RD)和死亡状态的马尔可夫模型。通过达到足够血清浓度的患者比例差异来模拟药物监测的效果。通过确定性和概率敏感性分析来测试模型假设变化对结果的稳健性。
在基线情况下，监测 endoxifen 可增加 0.0115 个质量调整生命年(QALY)，并为每个患者节省 1564 欧元。确定性敏感性分析表明，DFS 和 RD 状态之间的成本和效用差异对增量成本效益比(ICER)有很大影响。概率敏感性分析表明，在愿意为每个质量调整生命年(QALY)支付 0 欧元的情况下，成本效益的概率为 89.8%。
基于该模型，从医疗保健支付者的角度来看，监测用他莫昔芬治疗的辅助 ERα+乳腺癌患者的 endoxifen 可能会增加 QALY 并节省成本。我们建议临床医生考虑将血清 endoxifen 浓度监测纳入 ERα+乳腺癌患者的标准辅助他莫昔芬治疗中。
