Screening Circulating Tumor Cells as a Noninvasive Cancer Test in 3388 Individuals from High-Risk Groups (ICELLATE2)

Figure 1

(a) A circulating tumor cell prepared from a 7.5 ml blood sample from a 79-year-old male with no previous history of cancer. The cell is stained for cytokeratin (red) and for the cell nucleus (blue), typical of epithelial cells. Epithelial cells should not normally be present in the blood. The cell was negative for CD45, that is, not an immune cell. The cell nucleus has a large size typical of transcriptionally active cells, such as cancer cells, and the rounded shape of a cell in suspension, rather than the angular shape and cell sheath context of a normal solid tissue epithelium cell. (b) Three additional examples of circulating tumor cells stained for cytokeratin (red) and for the cell nucleus (blue). The lower magnification also shows the residual leucocytes surrounding the circulating tumor cells (blue nuclei, with no cytokeratin (red). The samples were enriched about 7500-fold for CTCs, with about 10,000 DAPI and CD45-positive leucocytes left in the sample after enrichment.

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