Detection of tumor cells in the portal and peripheral blood of patients with colorectal carcinoma using competitive reverse transcriptase-polymerase chain reaction

Abstract

BACKGROUND In spite of many reports, it remains unclear whether the presence of tumor cells in circulating blood flow predicts a poor prognosis. METHODS Competitive seminested reverse transcriptase‐polymerase chain reaction (RT‐PCR), a technique for the quantitative detection of tumor cells, was applied to detect the presence of tumor cells in portal and peripheral blood samples from 121 patients with colorectal carcinoma and to clarify their clinical significance. This technique can detect one carcinoembryonic antigen (CEA) mRNA‐expressing tumor cell in 1 × 105 normal lymphocytes. RESULTS Six of 33 healthy volunteers (18%) demonstrated a positive reaction to this technique. CEA mRNA expression was detected in the portal blood in 51% of patients and in the peripheral blood in 42% of patients. The results from the two blood samples were consistent in 91% of patients. The positive expression rates for portal blood in patients with T1 tumors and those with TNM Stage I disease were 38% and 45%, respectively. The positive rate was significantly higher in patients with colon carcinoma and those with Stage III or IV disease. CEA mRNA expression, quantitatively measured (× 10−8/β‐actin), was 22.9 ± 35.1 in the portal blood and 19.9 ± 40.0 in the peripheral blood, with no statistically significant difference. A significant positive correlation was noted between portal and peripheral CEA mRNA expression levels according to Speaman correlation analysis (correlation coefficient = 0.78; P < 0.01). Multivariate analysis revealed that the positive rate and level of CEA mRNA expression in the portal and peripheral blood did not appear to be influenced by the established prognostic factors. CONCLUSIONS The presence of circulating tumor cells might be of less value as a prognostic factor because they also can be detected in patients with early‐stage colorectal carcinoma and appeared to be independent of the conventional prognostic factors. Cancer 2001;92:1251–58. © 2001 American Cancer Society.

Establishment and Characterization of Mammalian Cell Lines Stably Expressing Human L-Type Amino Acid Transporters

“…The 7700 Sequence Detector System (Applied Biosystems) was used for Real-time quantitative RT-PCR (32,33). Briefly, each RT-PCR reaction mixture (50 μl) included 250 ng of total RNA, 25 μl of Taqman Universal PCR Master Mix (Applied Biosystems), 0.5 μl of forward and reverse primer (10 μM), and 1.0 μl of corresponding Taqman probe (5000 nM).…”

Serum sE‐selectin levels and carcinoembryonic antigen mRNA‐expressing cells in peripheral blood as prognostic factors in colorectal cancer patients

“…This observation may partially explain the negative conclusions reached by other authors, who suggested that the presence of circulating tumor cells might be of little value as a prognostic factor, because they appeared not to be associated with conventional prognostic factors, namely the presence of metastatic disease. 20 The findings here of a significant association between increased sE-selectin and positive CEA mRNA-expressing cells in the peripheral blood of patients with low-grade inflammatory status (as evidenced by increased levels of TNF-a) fuel the hypothesis that circulating tumor cells may, indeed, represent a prognostic factor, but only in those patients in whom they are capable of triggering the molecular changes demonstrated in the studies cited above, 6,7 and suggest that circulating tumor cells might be responsible for macrophage activation in vivo, release of proinflammatory cytokines, and up-regulation of vascular E-selectin, which can be detected in its soluble form on shedding from the endothelial cell surface. This hypothesis is also consistent with the finding that the highest sEselectin levels were detected in patients highly expressing CEA mRNA and with positive TNF-a levels compared with patients with negative levels of both variables.…”

Detection of Epithelial Cells by RT-PCR Targeting CEA, CK20, and TEM-8 in Colorectal Carcinoma Patients Using OncoQuick Density Gradient Centrifugation System

“…The association of tumorspecific mRNA detection in the peripheral blood with the various clinicopathological parameters has been a matter of significant debate. There is reported evidence to a significant association of disseminated cancer cell detection to advance stage and lymph node metastasis [21,45]. On the other hand, there are studies that no correlation can be detected between the CEA mRNA detection and the clinicopathological characteristics of the disease [7].…”