Use of Two Tumour Markers, Cytokeratin-20 and Carcinoembryonic Antigen, for Detection of Circulating Cancer Cells in Patients with Advanced Gastric Cancer

초록

Objective: The presence of cancer cells in the peripheral blood of cancer patients is important to decision on the treatment modality and prognosis of the patients. We used two tumor markers, cytokeratin-20 (CK-20) and carcinoembryonic antigen (CEA), simultaneously for detection of circulating cancer cells in patients with advanced gastric cancer in order to improve detection efficiency. Methods: From June 2000 to November 2001, one hundred nine patients had underwent curative operation for advanced gastric cancer with no systemic metastasis. Peripheral blood samples from all patients were collected and screened for expression of CK-20 and CEA mRNA by reverse transcritase-polymerase chain reaction (RT-PCR). Then the data were analyzed for association with various clinicopathological factors. Results: Of total 109 patients, 18 patients (16.5%) showed positive result for CK-20 mRNA, 18 patients (16.5%) for CEA mRNA, and only two patients (1.8%) for both. Overall positive rate for expression of any tumor marker was 31.2% (34/109). But the positive expression of tumor marker mRNAs didn’t show any significant association with the clinicopathological factors such as age, sex, Borrmann type, tumor location, histological grade, depth of invasion, lymph node status, and stage. Conclusion: Using two tumor markers, CK-20 and CEA, may increase the detection rate for circulating cancer cells. But we couldn’t find any correlation between the positive expression of tumor markers in blood and various clinicopathological factors. The roles of CK-20 and CEA as tumor markers for detection of circulating cancer cells should be evaluated further.