Quantitative real-time RT-PCR detection for CEA, CK20 and CK19 mRNA in peripheral blood of colorectal cancer patients.

This study is aimed at establishing a sensitive approach to detect disseminated tumor cells in peripheral blood and evaluate its clinical significance. A total of 198 blood samples including 168 from colorectal carcinoma (CRC) patients and 30 from healthy volunteers were examined by quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR) to evaluate the expression of carcinoembryonic antigen (CEA), cytokeratin 20 (CK20) and cytokeratin 19 (CK19) mRNA. CEA mRNA was detected in 35.8% of patients and 3.3% of controls, CK20 mRNA in 28.3% of patients and 6.7% of controls, and CK19 mRNA in 41.9% of patients and 3.3% of controls. CEA and CK20 mRNA positive ratio increased with the advancing Dukes stages, but there was no significant difference in positive ratio between any two stages (P>0.05). Also, relatively high positive ratio of CEA, CK20 and CK19 mRNA expression was observed in some CRC patients with earlier Dukes stages. A higher positive ratio was obtained when two or three detection markers were combined compared to a single marker. Our study indicates that quantitative real-time RT-PCR detection for CEA, CK20 and CK19 mRNA in peripheral blood is a valuable tool for monitoring early stage dissemination of CRC cells in blood circulation.

[Significance of CK20 mRNA expression in peripheral blood of colorectal cancer patients by real-time fluorescent quantitative RT-PCR].

OBJECTIVE: To detect the expression of cytokeratin 20 (CK20) mRNA in peripheral blood of colorectal carcinoma and to discuss its clinical value. METHODS: Real-time fluorescent quantitative RT-PCR was used to detect the CK20 mRNA expression in the peripheral blood of 51 patients with colorectal carcinoma and 30 healthy volunteers. RESULTS: 27.45% of the patients showed CK20 mRNA expression, while it was 6.67% for the control group (P<0.025). With the progress of Dukes' stages, the expression level of CK20 mRNA increased, but there was no statistic significance (P<0.05). More samples in Dukes'C and D than in Dukes'A and B stages showed >10 copies/ml. CONCLUSION: The detection of CK20 mRNA expression in peripheral blood of patients with colorectal carcinoma may be helpful to identify early shedding tumor cells. It is also useful to monitor the progression of the disease and observe the effect of clinical treatment.

[Combined detection of CEA mRNA and CK 19 mRNA in peripheral blood cells of patients with lung cancer].

OBJECTIVE: To investigate the expression of CEA mRNA and CK(19) mRNA in peripheral blood cells of patients with lung cancer and evaluate its clinical significance. METHODS: Peripheral blood nucleated cells of 50 patients with lung cancer were studied by RT-PCR to detect the expression of CEA mRNA and CK(19) mRNA. RESULTS: The combined positive rate of CEA mRNA and CK(19) mRNA in patients with lung cancer (82.0%) was significantly higher than that in patients with benign lung diseases (28.0%) and healthy volunteers (8.1%) (P < 0.001). The expression rate had no relation to the clinical staging or histological type. Compared with single detection, combined detection increased the detection rate but did not decrease the specificity. CONCLUSION: Combined detection of CEA mRNA and CK(19) mRNA expression in peripheral blood nucleated cells increase the sensitivity of detecting hematogenous dissemination of cancer cells. Long-term survival analysis and more specimens would be helpful for evaluating its clinical significance.

[Clinical significance of CEA mRNA detection in pleural and peritoneal effusions by real-time fluorescent quantitative RT-PCR].

OBJECTIVES: To detect CEA mRNA levels in benign and malignant pleural and peritoneal effusions and evaluate their clinical significance. METHODS: Samples of pleural and peritoneal effusions from 58 patients with malignant diseases and 76 patients with benign diseases were collected and total RNAs were prepared and subjected to real-time fluorescent quantitative RT-PCR to determine the CEA mRNA levels in these samples. The positive rate of this examination was compared with that of shed cell pathological examination. RESULTS: Nineteen samples (32.8%) of pleural and peritoneal effusions from the 58 patients with malignant diseases showed positive results in shed cell examination, while the number of CEA mRNA >1 CN was 46 (79.3%) (chi(2) = 21.81, P = 0.000). Nineteen samples of pleural and peritoneal effusions from the 76 patients with benign diseases showed CEA mRNA > 1 CN (25.0%), which was significantly different from that of the patients with malignant diseases (chi(2) = 38.85, P = 0.000). CONCLUSION: CEA mRNA levels in pleural and peritoneal effusions can be quantified by real-time fluorescent quantitative PCR, which is more sensitive than shed cell pathological examination. This technique is helpful in discrimination of benign and malignant pleural and peritoneal effusions.