Disseminated tumor cells versus micrometastasis: definitions and problems

Abstract

The finding of single tumor cells or small tumor cell groups in the lymph and blood (including bone marrow aspirations) should be designated as isolated or disseminated tumor cells. The UICC (1992) recommended to identify such findings by the addition of "(i)" (for isolated tumor cells). In contrast, micrometastasis (2 mm or less) should be indicated by the addition of "(mi)". Before introduction of the examination of lymph nodes or bone marrow aspirations regarding isolated (disseminated) tumor cells the methods have to be standardized and the clinical relevance (independent prognostic significance, assistance in selection of patients for adjuvant treatment) has to be evaluated in prospective large scale studies.