Background: The nationwide use of the 21-gene recurrence score (21-RS) and implications regarding chemotherapy administration in relation to clinical risk in early breast cancer patients are investigated. Methods: Breast cancer patients surgically treated between 2014 and 2016 were selected from the Netherlands Cancer Registry and categorized as having a clinical low, intermediate, or high risk of developing metastases. Deployment of the 21-RS is advocated in patients with an intermediate risk of developing metastases. The use and impact of the 21-RS test result on chemotherapy administration were assessed in relation to the clinical risk as well as patient and tumor characteristics; χ2 tests were used for analysis. Results: Of all patients, 20,488 were considered as clinical low-, 4,309 as intermediate-, and 15,266 as high-risk patients. The 21-RS was deployed in 0.1% (n = 23), 3.2% (n = 137), and 0.6% (n = 90) of these categories, respectively. In the clinical intermediate-risk group, the 21-RS assigned 73.7, 13.1, and 13.1% of patients to the genomic low-, intermediate-, and high-risk category, respectively. Adherence to the 21-RS was 95.6% in these patients. Conclusion: In the Netherlands, the 21-RS test is applied both inside and outside the guideline-directed area. In case of discordance between the genomic and clinical risk, patients were treated in line with the result of the 21-RS.

中文翻译：

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21 基因复发评分与荷兰早期乳腺癌患者发生转移的临床风险相关的使用和影响

背景：研究了 21 基因复发评分（21-RS）在全国范围内的使用，以及与早期乳腺癌患者临床风险相关的化疗管理的影响。方法： 2014 年至 2016 年间接受手术治疗的乳腺癌患者选自荷兰癌症登记处，并被归类为具有临床低、中或高发生转移风险的乳腺癌患者。建议在发生转移的中等风险患者中使用 21-RS。根据临床风险以及患者和肿瘤特征，评估了 21-RS 测试结果对化疗给药的使用和影响；χ2 检验用于分析。结果：在所有患者中，20,488 名被认为是临床低危患者，4,309 名被认为是中危患者，15,266 名被认为是高危患者。21-RS 分别部署在这些类别的 0.1% (n = 23)、3.2% (n = 137) 和 0.6% (n = 90) 中。在临床中危组中，21-RS 分别将 73.7%、13.1% 和 13.1% 的患者分配到基因组低危、中危和高危类别。这些患者对 21-RS 的依从性为 95.6%。结论：在荷兰，21-RS 测试适用于指南指导区域内外。如果基因组和临床风险不一致，则根据 21-RS 的结果对患者进行治疗。这些患者对 21-RS 的依从性为 95.6%。结论：在荷兰，21-RS 测试适用于指南指导区域内外。如果基因组和临床风险不一致，则根据 21-RS 的结果对患者进行治疗。这些患者对 21-RS 的依从性为 95.6%。结论：在荷兰，21-RS 测试适用于指南指导区域内外。如果基因组和临床风险不一致，则根据 21-RS 的结果对患者进行治疗。