[The detection of circulating hepatocellular carcinoma cells in peripheral venous blood by reverse transcription-polymerase chain reaction and its clinical significance].

OBJECTIVE: To detect circulating hepatocellular carcinoma by demonstrating hepatocellular carcinoma cells-associated mRNA in the nuclear cell component of peripheral blood (PBL). METHOD: Peripheral blood (5 ml) samples were obtained from 93 patients with hepatocellular carcinoma (HCC) and from 37 controls (15 controls with liver cirrhosis after hepatitis B, 12 chronic hepatitis B, and 10 normal liver function). To identify HCC cells in peripheral blood, liver-specific human alpha-fetoprotein (AFP) mRNA was amplified from total RNA extracted from whole blood by reverse transcription-polymerase chain reaction. RESULT: AFP mRNA was detected in 50 blood samples from the patients with HCC (53.8%). In contrast, there were no clinical control patients whose samples showed detectable AFP mRNA in PBL. The presence of AFP mRNA in blood seemed to be correlated with the stage (by TNM classification) of HCC, the serum AFP value, and the presence of intrahepatic metastasis, portal vein thrombosis, tumor diameter and/or distant metastasis. AFP mRNA was detected in the blood of 21 patients showing metastasis at extrahepatic organs (100%) in contrast to 29 of 72 patients without metastasis (40.3%). CONCLUSION: The presence of AFP mRNA in peripheral blood may be an indicator of malignant hepatocytes, which might predict hematogenous spreading metastasis of tumor cells in patients with HCC.