Takeru Shiroiwa, Takashi Fukuda, Kojiro Shimozuma, Mitsuko Mouri, Yasuhiro Hagiwara, Takuya Kawahara, Shozo Ohsumi, Yasuo Hozumi, Yoshiaki Sagara, Yasuo Ohashi, Hirofumi Mukai, Shiroiwa, Takeru, Fukuda, Takashi, Shimozuma, Kojiro, Mouri, Mitsuko, Hagiwara, Yasuhiro, Kawahara, Takuya, Ohsumi, Shozo, Hozumi, Yasuo, and Sagara, Yoshiaki
Background: This study evaluated the cost-effectiveness of replacing standard intravenous therapy (taxane) with oral S-1 therapy for first-line metastatic breast cancer treatment.Methods: This cost-effectiveness analysis was based on data from a randomized phase III trial (SELECT BC). As cost-effectiveness was a secondary endpoint of the SELECT BC trial, some of the randomized patients participated in an EQ-5D survey (N = 391) and health economic survey (N = 146). The EQ-5D responses, claims, and prescription data were collected for as long as possible until death. The expected quality-adjusted life years (QALY) obtained from each treatment were calculated using patient-level EQ-5D data, and the expected cost was calculated using patient-level claim data. The analysis was performed from the perspective of public healthcare payers.Results: The estimated EQ-5D least-square means and 95% CI up to 48 months were 0.764 (95% CI, 0.741-0.782) and 0.742 (95% CI, 0.720-0.764) in the S-1 and taxane arms, respectively. The expected QALY was 2.11 for the S-1 arm and 2.04 for the taxane arm, with expected costs of JPY 5.13 million (USD 46,600) and JPY 5.56 million (USD 50,500), respectively. These results show that S-1 is cost-saving. According to probabilistic sensitivity analysis, S-1 was dominant with a probability of 63%. When the willingness to pay (WTP) value was JPY 5 million (USD 45,500) per QALY, the probability of being cost-effective was 92%.Conclusions: Our results show that the introduction of oral S-1 therapy for metastatic breast cancer is highly likely to be cost-effective.Trial Registration: UMIN CTR C000000416 . Registered on May 10, 2006. [ABSTRACT FROM AUTHOR]