Molecular Detection of Disseminated Tumor Cells in the Peripheral Blood of Patients with Gastric Cancer: Evaluation of Their Prognostic Significance

Abstract

Early detection of disseminated tumor cells in the peripheral blood of patients with early stage gastric cancer could help to improve the outcome after tumor resection. The aim of this study is to evaluate the prognostic significance of tumor-related mRNA for the detection of circulating tumor cells in gastric cancer patients by a reverse-transcriptase polymerase chain reaction (RT-PCR) method. We simultaneously analyzed human telomerase reverse transcriptase (hTERT), cytokeratin-19 (CK-19), cytokeratin-20 (CK-20) and carcinoembryonic antigen (CEA) mRNA (messenger RNA) expression in the peripheral blood of 42 gastric cancer patients and 30 healthy individuals. Additionally, analyses were carried out for the correlation of these four molecular markers with patients’ clinicopathologic features, as well as the occurrence of postoperative recurrence/metastasis. Among 42 gastric cancer patients, the prevalence of mRNA for hTERT, CK-19, CK-20, and CEA was 61.9% (26/42), 69% (29/42), 61.9% (26/42), and 78.6% (33/42), respectively. All 30 healthy individuals were negative for hTERT and CEA mRNA, while two were positive for either CK-19 mRNA or CK-20 mRNA. Positive CEA mRNA was significantly correlated with tumor size (p = 0.008), vessel invasion (p = 0.001), depth of tumor invasion (p = 0.007), lymph node metastasis (p < 0.001), and TNM stage (p < 0.001). In addition, the multivariate logistic regression demonstrated that CEA mRNA expression was an independent and significant predictor for postoperative recurrence/metastasis (p = 0.032). Our findings suggest that CEA mRNA may be a more reliable marker than hTERT, CK-19 and CK-20 for the detection of circulating cancer cells in gastric cancer patients' peripheral blood. Patients with positive CEA mRNA expression in peripheral blood have a significantly higher risk of postoperative recurrence/metastasis.

Development of a high‐throughput membrane‐array method for molecular diagnosis of circulating tumor cells in patients with gastric cancers

“…With membrane array, we observed that the detection rates of using single markers for CTCs in GC patients ranged from 78.1% to 82.8%, apparently higher than the results with RT-PCR (61.9-78.6%) in our previous observation 25 or those in another investigation (35.5-51.6%). 13 This indicates that this highly sensitive, high-throughput method can serve as an appropriate tool for GC detection.…”

“…We have demonstrated previously that RT-PCR of CEA mRNA marker was a highly sensitive approach for CTCs detection in GC patients. 25 Additionally, a panel of molecular markers could enhance the sensitivity for CTCs detection, compared with single markers in use. 21 RT-PCR assay is by far regarded widely to be the most sensitive method for detecting tumor-associated molecular markers.…”

Circulating tumor cells: advances in detection methods, biological issues, and clinical relevance

“…CTC-positive rate based on CEA mRNA marker was well correlated with postoperative recurrence, tumor size, vascular invasion, depth of tumor invasion, lymph node metastasis, and TNM stage (Wu et al 2006). Earlier study got the similar data (Seo et al 2005).…”

Evaluation of MUC1, CK20, and hTERT expression in peripheral blood of gastrointestinal cancer patients in search of diagnostic criteria

“…Other studies showed MUC1, CK20, and hTERT expressions in peripheral blood of healthy individuals (de Cremoux et al, 2000;Gradilone et al, 2003;Uen et al, 2006;Wu et al, 2006;Wang et al, 2007). Illegitimate transcription of tissue-specific genes in blood from healthy individuals has been previously described by the mononuclear fraction.…”