Comparative cost-effectiveness of radiotherapy among older women with hormone receptor positive early-stage breast cancer

The aim was to examine the real-world cost-effectiveness of breast-conserving surgery (BCS) plus hormonal therapy with radiotherapy, compared to hormonal therapy alone among women 66 and older with hormone receptor positive early-stage breast cancer in the United States (US). This study was conducted from a U.S. Centers for Medicare and Medicaid Services perspective and an eight-year time horizon. Both costs (2020 US$) and health utilities (quality-adjusted life years, QALYs) were obtained from retrospective studies using the SEER linked with Medicare and Medicare Health Outcomes Survey, respectively. The incremental cost-effectiveness ratio (ICER) of the addition of radiotherapy to hormonal therapy versus hormonal therapy alone after BCS was estimated by an unbiased doubly robust estimator. Sensitivity analyses were conducted through bootstrapping to estimate credible intervals. The addition of radiotherapy to hormonal therapy after BCS yielded the highest clinical benefits (2.66 QALYs) and costs ($19,424.27) compared to its hormonal therapy alone after BCS (0.77 QALYS; $2,028.58). The ICER was estimated to be $9,174.94/QALY. Sensitivity analyses did not change the direction of the findings. The results implicated that the combination of radiotherapy and hormonal therapy is cost-effective in the US.