OBJECTIVE: To evaluate the clinical significance of CK20 mRNA expression in detecting disseminated tumor cells in peripheral blood of gastric and colorectal cancer patients. METHODS: Expression of CK20 mRNA was investigated by RT-PCR in bone marrow, portal vein and peripheral blood in 47 gastric, 58 colorectal cancer patients and 6 non-cancer volunteers. All the patients were followed-up for one year. RESULTS: There was no positive expression of CK20 mRNA in 6 non-cancer volunteers. The positive rates of CK20 mRNA in bone marrow, portal vein were 87.2% (41/47) and 85.1% (40/47) in gastric cancer, and were 77.6% (45/58) and 74.1% (43/58) in colorectal cancer. The positive rates of CK20 mRNA in peripheral blood in gastric and colorectal cancer patients were 42.6% (20/47) and 44.8% (26/58) by one single test, and were 74.5% (35/47) and 69.0% (40/58) by two tests. The overall positive rate of CK20 mRNA in peripheral blood (two tests) was similar to that in bone marrow and portal vein. The overall positive rate of CK20 mRNA in peripheral blood was higher in two tests than in one single test (P < 0.05) and in advanced than early lesions. The relapse rate within one year was higher in CK20 mRNA positive patients than the negative ones (P < 0.05). CONCLUSION: Detection of cancer cells by RT-PCR for CK20 mRNA in peripheral blood, being as sensitive and specific as in bone marrow and portal vein, is reliable and convenient in diagnosing micrometastasis of gastric and colorectal cancer, which possesses clinical significance in assessing the prognosis and scheme of therapy.
OBJECTIVE: To evaluate the clinical significance of CK20 mRNA expression in detecting disseminated tumor cells in peripheral blood of gastric and colorectal cancerpatients. METHODS: Expression of CK20 mRNA was investigated by RT-PCR in bone marrow, portal vein and peripheral blood in 47 gastric, 58 colorectal cancerpatients and 6 non-cancer volunteers. All the patients were followed-up for one year. RESULTS: There was no positive expression of CK20 mRNA in 6 non-cancer volunteers. The positive rates of CK20 mRNA in bone marrow, portal vein were 87.2% (41/47) and 85.1% (40/47) in gastric cancer, and were 77.6% (45/58) and 74.1% (43/58) in colorectal cancer. The positive rates of CK20 mRNA in peripheral blood in gastric and colorectal cancerpatients were 42.6% (20/47) and 44.8% (26/58) by one single test, and were 74.5% (35/47) and 69.0% (40/58) by two tests. The overall positive rate of CK20 mRNA in peripheral blood (two tests) was similar to that in bone marrow and portal vein. The overall positive rate of CK20 mRNA in peripheral blood was higher in two tests than in one single test (P < 0.05) and in advanced than early lesions. The relapse rate within one year was higher in CK20 mRNA positive patients than the negative ones (P < 0.05). CONCLUSION: Detection of cancer cells by RT-PCR for CK20 mRNA in peripheral blood, being as sensitive and specific as in bone marrow and portal vein, is reliable and convenient in diagnosing micrometastasis of gastric and colorectal cancer, which possesses clinical significance in assessing the prognosis and scheme of therapy.