ABSTRACT
BACKGROUND & OBJECTIVE: Detecting expression levels of cytokeratin 19 (CK19), CK20, MUC1, and carcinoembryonic antigen (CEA) in peripheral blood,lymph node,and bone marrow is a major method for diagnosing micro-metastasis in patients with gastrointestinal carcinoma of early stages. This study was to examine the expression, before and after operation, of CK20 mRNA in peripheral blood of patients with gastrointestinal carcinoma, to further explore hematogenous-spread micro-metastasis status of these patients, and significance of CK20 mRNA detection in treatment during perioperation period. METHODS: Peripheral blood samples were collected before, and 2 weeks after operation from 62 patients with gastrointestinal carcinoma,and 22 controls (12 patients with benign gastrointestinal disease, and 10 healthy volunteers). CK20 mRNA expression in the blood samples was specifically detected by nested reverse transcriptase-polymerase chain reaction (RT-PCR). Pathologic examination of all cases was done by conventional methods. RESULTS: Of 62 patients with gastrointestinal carcinoma, 34 (54.3%) have positive CK20 mRNA expression before operation,and so did 31 (50.0%) postoperatively, but no CK20 mRNA expressed in 22 controls. In patients of stageI-IV, CK20 mRNA positive rates were 37.5% (3/8), 36.3% (8/22), 66.7% (18/27), and 100% (5/5), respectively, difference between stage I+II (36.9%) and stage III+IV (83.3%) was significant (P< 0.05). Among 35 patients with local lymph node metastasis, 27 (77.1%) were positive for CK20 mRNA; among 27 patients without lymph node metastasis, 7 (25.9%) have positive CK20 mRNA expression (P< 0.01). CK20 mRNA expression was not correlated with tumor cell differentiation,and cancer embolus existance. There was no significant difference in CK20 mRNA expression before and after operation (P >0.05). CONCLUSIONS: CK20 mRNA may be a sensitive marker for detecting micro-metastasis,and recurrence of patients with gastrointestinal carcinoma. It may be helpful for the correct clinical staging,and reasonable treatment for patients.
