The frequency of circulating or tumour-infiltrating regulatory T cells (Tregs) has been associated with poor patient survival in many cancers including breast, melanoma and lung. It has been hypothesised that Tregs impact the anti-tumour function of effector T cells, resulting in worse outcomes for patients. However, high infiltrates of Tregs have been associated with a positive outcome of patients in a minority of cancers including colorectal, bladder and oesophageal. In addition, many studies have shown no impact of Tregs in patient outcome. Traditionally, research has identified Tregs as forkhead box P3 (FOXP3+) T cells in order to make such associations. Recently, it has become evident that regulatory populations are very heterogeneous, and this heterogeneity is essential for Treg function. Treg heterogeneity likely affects predictions of patient outcome, and different Treg populations may have different influences on tumours. The study of Tregs in cancer must include a better definition of the cells analysed. This review will focus primarily on colorectal cancer in humans, due to mixed data on the impact of Tregs on patient outcome in this disease.

中文翻译：

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调节性T细胞异质性和癌症免疫反应。

在包括乳腺癌，黑色素瘤和肺癌在内的许多癌症中，循环或肿瘤浸润性调节性T细胞（Tregs）的发生率与患者存活率低有关。已经假设Treg影响效应子T细胞的抗肿瘤功能，导致患者的预后较差。然而，Tregs的高度浸润与少数癌症（包括大肠癌，膀胱癌和食道癌）患者的阳性结果相关。此外，许多研究表明Treg对患者预后没有影响。传统上，研究已将Tregs识别为叉头盒P3（FOXP3 +）T细胞，以建立这种关联。最近，已经变得明显的是，调节种群非常异质，这种异质性对于Treg功能至关重要。Treg异质性可能会影响患者预后的预测，并且不同的Treg人群可能会对肿瘤产生不同的影响。对癌症中Treg的研究必须包括对所分析细胞的更好定义。由于关于Tregs对该疾病患者预后的影响的混合数据，本综述主要关注人的结肠直肠癌。