Tumorsejter

Tumorsejter is a term used in some experimental oncology literature to describe small aggregates of malignant cells that detach from a primary tumor and move through the bloodstream or lymphatic system with the potential to seed distant sites. The term is not standardized and is not part of conventional diagnostic nomenclature. In this usage, tumorsejter refers to microclusters of two or more tumor cells, sometimes accompanied by non-tumor components such as platelets or stroma, distinguishing them from single circulating tumor cells.

Biology and formation: The formation of clusters is thought to involve partial epithelial-to-mesenchymal transition, preserved cell–cell adhesion, and interactions with blood components that protect cells from shear stress and immune attack. Clusters may have higher survival during circulation and greater metastatic efficiency than single cells. Tumorsejter is typically used when a study emphasizes the collective biology of these aggregates rather than isolated cells.

Clinical relevance and detection: In research settings, tumorsejter are sometimes detected in blood samples using specialized microfluidic devices, immunostaining, or sequencing approaches capable of identifying cell clusters. Because the concept is not universally adopted, definitions and detection criteria vary. Some studies associate tumor cell clusters with worse prognosis, but robust clinical validation is limited and there is no standard diagnostic use.

Relationship to existing concepts: Tumorsejter overlaps with, but is not identical to, circulating tumor cell (CTC) clusters. The term remains informal and is not part of routine pathology or oncology practice.