Expert Commentary & Five-year View
Immense progress has been achieved in recent years in development of novel techniques for the study of CTCs in cancer patients. Through these advances, we now have a wider variety of tools for interrogation of CTC characteristics. While most previous efforts were focused on the enumeration of CTCs and its correlation with clinical findings, we could now characterize CTCs at a deeper level such as the differential expression of markers between CTC and the primary tumor and the occurrence of EMT in CTCs. It is also now possible to focus on examining viable CTCs which would definitely help further our understanding of CTC biology. Undoubtedly, these achievements would not have been possible were it not for developments of new markers and tools which have allowed us to study CTCs with greater specificity, sensitivity and purity. However, there are still problems ahead such as our lack of ability to profile the entire population of CTCs in a patient's blood and the lack of large-scale validation of most of our methodologies. The recent application of novel methodologies for transcriptomic[129,130] and mutational analyses[131,132] of CTCs at the single cell level is expected to greatly advance our understanding of CTC biology. It is hoped that in the next few years, we would be able to study CTCs at the single cell level such that we could better define the most important properties of CTCs which ultimately lead to development of metastasis and thus help reduce cancer-related mortalities.
Expert Rev Proteomics. 2013;10(6):579-589. © 2013 Expert Reviews Ltd.