The relevance of RT-PCR detection of disseminated tumour cells is hampered by the expression of markers regarded as tumour-specific in activated lymphocytes

Detection of isolated tumour cells in the blood and bone marrow of patients with gastric cancer by combined sorting, isolation and determination of MAGE-1, -2 mRNA expression

“…This feature, coupled with a highly sensitive real-time nested PCR, further helps to identify a tumour cell with an even higher probability, though the deficient expression of the marker gene in micrometastatic tumour cells (30) remains a problem. It should be kept in mind, that the detection of molecular tumour markers alone without the proper identification of their cellular origin may not necessarily indicate their malignant nature as several tumour-associated antigens may be expressed by activated lymphocytes (24). Thus, enrichment, identification and isolation of CK + cells and the determination of tumourassociated gene expression makes this method more reliable than the use of molecular methods alone applied to the whole blood or bone marrow samples.…”

“…Furthermore, the false positive mRNA signals may derive from other (non-tumour) cells, e.g. PSA mRNA expressed by blood monocytes (23) or squamous cell carcinoma antigen and epidermal growth factor receptor mRNAs on activated lymphocytes which are present in some cancer patients (24), while false negative signals may arise from the diluting out of specific mRNA by coextracted RNA from other cells. ONCOLOGY REPORTS 19: 1055-1060, 2008 Detection of isolated tumour cells in the blood and bone marrow of patients with gastric cancer by combined sorting, isolation and determination of MAGE-1, -2 mRNA expression With the introduction of the Laser Capture Microdissection System (LCM), a new possibility for ITC detection emerged.…”

Carcinoembryonic antigen and cytokeratin 20 in peritoneal cells of cancer patients: are we aware of what we are detecting by mRNA examination?

“…In our opinion, there are no grounds for this presumption. We and others have raised the issue of the nonspecific expression of so-called tumour markers by activated lymphoid cells (Kowalewska et al, 2006). CEA and CK 20 transcripts are markers of limited value for the detection of cancer cells for several reasons.…”

Circulating tumor cells in gastric cancer

“…Nowadays, a multiplex RT-PCR approach combined with liquid bead array detection has been developed to perform simultaneous amplification and detection of multiple biomarkers. However, there are several limitations, such as the contamination of non-malignant cells, the high rate of false positives, and amplification of cell-free nucleic acids [34] . In addition, once RNA has been collected from cells, the cells cannot undergo advanced analysis.…”