OBJECTIVEAs our previous comparative proteomics study on high and low metastasis human hepatocellular carcinoma (HCC) cell strains revealed that cytokeratin 19 (CK19) was related to higher metastasis potential, we further investigated the relationship between serum CK19 level in HCC patients and their clinico-pathologic characteristics.

METHODSSerum CK19 levels of 101 normal controls and 108 pathology-proven HCC patients were determined using radioimmunoassay, and the their correlation with clinico-pathologic parameters were studied.

RESULTSThe upper limit of one-side 98% confidence interval of normal serum CK19 level was 2.3 microg/L. Among 108 HCC patients, 24 (22.2%) had increased serum CK19 level, ranging from 2.4 to 45.5 microg/L. There were 12 patients (11.1%) with increased CK19 level but normal AFP level. The percentage of poor differentiated tumor was higher in CK19 increased cases (37.5%, 9/24) than in CK19 normal cases (20.2%, 17/84). Moreover, the presence of portal vein tumor emboli was significantly higher in CK19 increased cases (25.0%, 6/24) than in CK19 normal cases (6.0%, 5/84). (Chi-square = 7.403, P < 0.01) In addition, the percentage of TNM stage III/IV tumor was significantly higher in CK19 increased patients (54.2%, 13/24) than in CK19 normal cases. (chi-square = 13.300, P < 0.005)

CONCLUSIONSome HCC patients do have increased serum CK19 level, which could be related to portal vein tumor emboli, poor tumor differentiation and advanced tumor stages.