Background

We have previously demonstrated S-1 is non-inferior to taxane with respect to overall survival as first-line chemotherapy for HER2-negative metastatic breast cancer. We aimed to confirm whether S-1 is also non-inferior to anthracycline-containing regimens in the same setting.

Methods

We conducted an open-label, non-inferiority, Phase 3 study. Individuals who had HER2-negative metastatic breast cancer, had received no chemotherapy for advanced disease and had endocrine therapy resistance, were randomly assigned to the anthracycline-containing regimens or S-1. The primary endpoint was overall survival. A pre-planned combined analysis of our two Phase 3 studies was also carried out.

Results

We enrolled 230 patients (anthracycline, n = 115; S-1, n = 115). Median overall survival was 30.1 months (95% CI 24.9–35.8) with the S-1 group and 33.7 months (95% CI 25.5–36.9) with the anthracycline group. The HR for the anthracycline group was 1.09 (95% CI 0.80–1.48). The combined analysis constituted 814 patients (395 assigned to standard treatment (anthracycline or taxane); 419 assigned to S-1). Median overall survival was 36.3 months in the standard treatment group and 32.7 months in the S-1 group. S-1 was non-inferior to standard treatment in terms of overall survival (HR 1.06 (95% CI 0.90–1.25); P non-inferiority = 0.0062).

Conclusions

S-1 could be considered a new treatment option for first-line chemotherapy for patients with HER2-negative metastatic breast cancer.

Clinical trial registration

The University Hospital Medical Information Network, Japan: UMIN000005449. This trial was registered on 15 April, 2011.

中文翻译：

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含蒽环类药物的方案或紫杉烷与 S-1 作为转移性乳腺癌的一线化疗方案

背景

我们之前已经证明 S-1 作为 HER2 阴性转移性乳腺癌的一线化疗在总生存期方面不劣于紫杉烷。我们旨在确认 S-1 在相同情况下是否也不劣于含蒽环类药物的方案。

方法

我们进行了一项开放标签、非劣效性的 3 期研究。患有 HER2 阴性转移性乳腺癌、未接受晚期疾病化疗且对内分泌治疗耐药的个体被随机分配到含蒽环类药物的方案或 S-1 组。主要终点是总生存期。我们还对我们的两项 3 期研究进行了预先计划的综合分析。

结果

我们招募了 230 名患者（蒽环类药物，n  = 115；S-1，n  = 115）。S-1 组的中位总生存期为 30.1 个月（95% CI 24.9-35.8），蒽环类药物组为 33.7 个月（95% CI 25.5-36.9）。蒽环类药物组的 HR 为 1.09（95% CI 0.80-1.48）。综合分析包括 814 名患者（395 名分配到标准治疗（蒽环类或紫杉烷类）；419 名分配到 S-1）。标准治疗组的中位总生存期为 36.3 个月，S-1 组为 32.7 个月。S-1 在总生存期方面不劣于标准治疗（HR 1.06 (95% CI 0.90–1.25)；P非劣效性 = 0.0062）。

结论

S-1可被视为HER2阴性转移性乳腺癌患者一线化疗的新治疗选择。

临床试验注册

日本大学医院医疗信息网：UMIN000005449。该试验于 2011 年 4 月 15 日注册。