肿瘤萌芽（TB）是指与肿瘤前沿无连续性的单个或小团肿瘤细胞。差分集群（PDCs）较大且定性不同。TB级别和PDCs可能预测结肠直肠癌和其他癌症的不良预后，并属于“浸润前预后标记”的范畴，其中还包括肿瘤内基质类型。上皮间充质转化（EMT）使上皮细胞获得细胞间连接异常、迁移和基质侵袭等间质特征。TB和PDCs在EMT相关蛋白和RNA上存在变异，可能是EMT的形态表现。然而，TB和PDCs中上皮样特征的持续存在和缺乏典型变异的完整完成，可能表明“部分EMT”，即一种中间/混合状态。最近，Pavlič等人认为结直肠癌中的TB和PDCs代表部分EMT的不同表现，并且或许有争议的是，TB比PDCs更接近完整转化。在临床实践中，浸润前预后标记的观察者间一致性较低是一个潜在问题。英国结直肠癌病理数据集建议评估TB，并推荐使用国际共识系统，但时间将证明我们是否在采用可靠的预后标记或是重复造轮子。对TB、PDCs和EMT的进一步研究可能会更深入地了解它们在肿瘤发展和进展中的作用。©2023作者。Journal of Pathology由John Wiley & Sons Ltd代表大不列颠和爱尔兰病理学会出版。

Tumour budding (TB) describes single or small groups of neoplastic cells that lack continuity with an advancing tumour front. Poorly differentiated clusters (PDCs) are larger and qualitatively different. TB grade and PDCs may predict a worse outcome in colorectal carcinoma and other cancers and fall into the category of 'invasive front prognostic markers' that also includes intratumoural stroma type. Epithelial-mesenchymal transition (EMT) allows the adoption by epithelial cells of mesenchymal characteristics such as dyscohesion, migration, and stromal invasion. TB and PDCs harbor alterations in EMT-related proteins and RNAs and may be morphological manifestations of EMT. However, persistence of epithelioid features and absence of a full complement of typical alterations in TB and PDCs may indicate 'partial EMT', i.e. an intermediate/hybrid state. Recently, Pavlič et al asserted that TB and PDCs in colorectal cancer represent different manifestations of partial EMT and, perhaps controversially, that TB is closer than PDCs to complete transition. In clinical practice, low inter-observer agreement for invasive front prognostic markers is a potential problem. The UK colorectal cancer pathology dataset advises assessment of TB and recommends the use of an international consensus system, but time will tell if we are adopting reliable prognostic markers or reinventing the wheel. Additional studies of TB, PDCs, and EMT will presumably allow greater insight into their role in tumour development and progression. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.© 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.