Circulating tumour cells: the evolving concept and the inadequacy of their enrichment by EpCAM-based methodology for basic and clinical cancer research.
Cancer Diagnosis technologies are changing the healthcare scenario worldwide with huge socioeconomic impact. As we move into an era of individual personalized treatment the need for more sophisticated cancer diagnostics has emerged [1,2]. To date, cancer diagnosis and metastasis monitoring is mainly carried out through tissue biopsy and/or re-biopsy, a very invasive procedure limited only to certain locations and not always feasible in clinical practice . Tissue biopsy only yields information about a very small area of tumor at the time of extraction and in some cases it is difficult or impossible to obtain the tissue sample . The invasive nature of a biopsy poses a risk to patients and can have a significant cost . The mere analysis of primary tumor alone may not yield sufficient information for making critical treatment decisions. There are several reports that many cases of NSCLC do not yield accessible tissue . Additionally the limitations of tissue procurement for genetic testing in certain cancers such as non small cell lung cancer (NSCLC) have necessitated the development of non-invasive techniques to study the primary tumor .