Heterogeneity in breast carcinomas can be appreciated at various levels, from morphology to molecular alterations, and there are well-known genotypic-phenotypic correlations. Clinical decision-making is strictly focused on the evaluation of tumor cells and is based on the assessment of hormone receptors and of the HER2 status, by means of a combination of immunohistochemical and in situ hybridization techniques. The tumor microenvironment (TME) also shows a multifaceted nature stemming from the different actors populating the intratumoral and the peritumoral stroma of breast carcinomas. Of note, we have now evidence that tumor-infiltrating lymphocytes (TILs) are clinically meaningful as their quantification in the intratumoral stroma strongly correlates with good prognosis, in particular in triple-negative and HER2-positive breast cancer patients. Nevertheless, TILs are just one of the many actors orchestrating the complexity of the TME, which is populated by immune and non-immune cells (cancer-associated fibroblasts, cancer-associated adipocytes), as well as non-cellular components such as chemical inflammation mediators. In this review article we will overview the main features of the distinct cell compartments by discussing (i) the potential impact the TME may have on the prognostic stratification of breast cancers and (ii) the possible predictive value of some markers in the context of immunotherapy in light of the recent results of phase III studies in advanced and early triple-negative breast cancer patients.

中文翻译：

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乳腺癌肿瘤微环境的多方面性质


乳腺癌的异质性可以在从形态到分子改变的各个层面上认识到，并且存在众所周知的基因型-表型相关性。临床决策严格集中于对肿瘤细胞的评估，并基于对激素受体和 HER2 状态的评估，通过免疫组织化学和原位杂交技术相结合。肿瘤微环境（TME）还表现出多方面的性质，源于乳腺癌瘤内和瘤周基质中的不同作用者。值得注意的是，我们现在有证据表明肿瘤浸润淋巴细胞 (TIL) 具有临床意义，因为它们在瘤内基质中的定量与良好预后密切相关，特别是在三阴性和 HER2 阳性乳腺癌患者中。然而，TIL 只是协调 TME 复杂性的众多参与者之一，TME 由免疫和非免疫细胞（癌症相关成纤维细胞、癌症相关脂肪细胞）以及非细胞成分（例如化学炎症）组成。调解员。在这篇综述文章中，我们将通过讨论 (i) TME 对乳腺癌预后分层的潜在影响和 (ii) 免疫治疗背景下某些标志物的可能预测价值来概述不同细胞区室的主要特征鉴于晚期和早期三阴性乳腺癌患者的 III 期研究的最新结果。