Circulating tumor cells (CTCs) are known to exist in peripheral blood at ultra-low concentrations of patients with carcinomas, estimated to be around one in ten million normal blood cells. While existing technology can identify CTCs and correlate them with disease, no method has sufficient sensitivity to reliably measure a statistically significant number of cells at early stages of the disease where treatment can be most effective. Today’s best practices detect immunocytochemically labeled tumor cells using optical scan technologies, and some enable reexamination of the cells for pathological confirmation. However without cell enrichment, scan rates are far too slow for analysis of the sufficiently large population of cells needed to be statistically relevant.
We have developed an instrument that can directly scan and analyze 50 million nucleated cells and find rare cells in less than two minutes without using antigen-dependent enrichment technology. This performance is 500 times faster than other cell-based scan approaches and results from the instrument’s exceptionally wide field of view enabled by the use of fiber-optic array scanning technology (FAST). Additionally, we have developed a sample preparation method that is optimized for minimal cell loss and maximal retention of all CTCs. The developed instrument and preparation method will be used to investigate the prevalence of CTCs in both early stage and metastatic cancer patients.