Adjuvant endocrine therapy represents the standard of care for almost all HR+/HER2- breast cancers and different agents and durations are currently available. In this context, the tailoring and optimization of adjuvant endocrine treatment by reducing unnecessary toxic treatment while taking into account the biological heterogeneity of HR+/HER2- breast cancer represents a clinical priority. There is therefore a significant need for the integration of biological biomarkers in the choice of adjuvant endocrine therapy beyond currently used clinicopathological characteristics. Several gene-expression assays have been developed to identify patients with HR+/HER2- breast cancer who will not derive benefit from the addition of adjuvant chemotherapy. By enhancing risk stratification and predicting therapeutic response, genomic assays have also shown to be a promising tool for optimizing endocrine treatment decision. We here review evidence supporting the use of most common commercially available gene-expression assays (Oncotype DX, MammaPrint, Breast Cancer Index, Prosigna and EndoPredict) in tailoring adjuvant endocrine therapy. Available data on the use of genomic tests to inform extended adjuvant treatment choice based on the risk of late relapse and on the estimated benefit of a prolonged endocrine therapy are discussed. Moreover, preliminary evidence regarding the use of genomic assays to inform de-escalation of endocrine treatment, such as shorter durations or omission, for low risk patients are reviewed. Overall, gene expression assays are emerging as potential tools to further personalize adjuvant treatment for patients with HR+/HER2- breast cancers.

中文翻译：

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基因表达测定为 HR+/HER2- 乳腺癌制定辅助内分泌治疗

辅助内分泌治疗代表了几乎所有 HR+/HER2- 乳腺癌的护理标准，目前有不同的药物和持续时间。在这种背景下，通过减少不必要的毒性治疗同时考虑HR+/HER2-乳腺癌的生物异质性来定制和优化辅助内分泌治疗是临床优先考虑的问题。因此，除了目前使用的临床病理学特征外，在辅助内分泌治疗的选择中迫切需要整合生物标志物。已经开发了几种基因表达测定法来识别 HR+/HER2- 乳腺癌患者，这些患者不会从辅助化疗中获益。通过加强风险分层和预测治疗反应，基因组检测也被证明是优化内分泌治疗决策的有前途的工具。我们在这里回顾支持使用最常见的商业基因表达检测（Oncotype DX、MammaPrint、乳腺癌指数、Prosigna 和 EndoPredict）来定制辅助内分泌治疗的证据。讨论了使用基因组测试根据晚期复发风险和长期内分泌治疗的估计益处来告知延长辅助治疗选择的现有数据。此外，还审查了有关使用基因组检测来告知低风险患者内分泌治疗降级的初步证据，例如缩短疗程或省略治疗。总体而言，基因表达检测正在成为 HR+/HER2- 乳腺癌患者进一步个性化辅助治疗的潜在工具。