Clinical Utility of Circulating Tumor Cells – A Clinician’s Current View

Abstract

With the advent of technology that can reliably detect them, interest in circulating tumor cells have escalated with over 18,000 publications and its involvement in 911 trials. Its presence in the blood stream connotes more aggressive and serious disease. This has led to a revision in the American Joint Commission on Cancer TNM classification for breast cancer. Presence of circulating tumor cells upcodes presumed non-metastatic breast cancer (M0) to an intermediate stage M0(i+). This review will describe the methods to capture and detect circulating tumor cells with a focus on the most analytically valid system -CellSearch. The studies underpinning the established uses of CTC enumeration in prognosis of metastatic cancers (breast, prostate and colon) will be highlighted as well as the imminent deployment in early breast cancer. Emerging applications in monitoring cancer treatment and promising indications in other cancers will also be examined.

Detection of IDH mutations in cerebrospinal fluid: A discussion of liquid biopsy in neuropathology

“…CTC's are tumour-derived cells that have entered the bloodstream (or in some special cases of malignant brain tumours, into the cerebrospinal luid). They have the advantage of being representative of the genome of tumours known to be homogeneous, such as gastric carcinoma [15], and provide more analytic material for various 'omics' studies such as cell proteins and mRNA [16,17]. Quanti ication of CTC's also is a reasonably accurate tool for gauging tumour burden, disease progression or regression [17].…”

“…They have the advantage of being representative of the genome of tumours known to be homogeneous, such as gastric carcinoma [15], and provide more analytic material for various 'omics' studies such as cell proteins and mRNA [16,17]. Quanti ication of CTC's also is a reasonably accurate tool for gauging tumour burden, disease progression or regression [17]. However, the minuscule numbers of circulating tumour cells entering the systemic circulation make their study subject to sampling bias when characterising the heterogeneous genomic landscape within malignant tumours, particularly one as biologically aggressive as adult high-grade glioma [17][18][19].…”

“…Quanti ication of CTC's also is a reasonably accurate tool for gauging tumour burden, disease progression or regression [17]. However, the minuscule numbers of circulating tumour cells entering the systemic circulation make their study subject to sampling bias when characterising the heterogeneous genomic landscape within malignant tumours, particularly one as biologically aggressive as adult high-grade glioma [17][18][19].…”

“…Although there is well-established clinical utility in using pure quanti ication methods of circulating tumour cells to prognosticate breast, renal, prostate and colon cancers, the evidence on applying such an approach to gliomas is lacking [17,20,22], re lecting the novelty of this approach. Studies that attempt to elucidate clinically useful genomic mutations from glioma CTC's are also relatively lacking, with most studies of CTC's in glioma focusing on their epithelial to mesenchymal transition abilities and their possible role in tumorigenesis.…”