Quantification of α1-fetoprotein mRNA in peripheral blood and bone marrow: a tool for perioperative evaluation of patients with hepatocellular carcinoma

Background/aims: Quantification of α1-fetoprotein (AFP) mRNA in the blood using reverse transcriptase polymerase chain reaction (RT-PCR) could be a useful tool in monitoring the dynamics of minimal residual disease in patients with hepatocellular carcinoma (HCC). Since all available assays do not take into account the efficiency of cell separation, RNA extraction and reverse transcription, a competitive RT-PCR assay for quantification of AFP mRNA in relation to the housekeeping gene glyceraldehyde phosphate dehydrogenase (GAPDH) was established. Patients and methods: Peripheral blood of 22 patients and bone marrow aspirates of 11 patients with hepatocellular carcinoma was monitored perioperatively. Eighteen patients with other hepatic tumours or non-malignant hepatic diseases and 26 healthy blood donors served as controls. Messenger RNA contents were calculated relative to the content of GAPDH mRNA as an indicator of total cell count. Results: Among HCC patients, 6 of 22 (26%) were positive for AFP mRNA before operation with values ranging from 2 ag/100 fg to 36 ag/100 fg GAPDH mRNA (mean 14). Among bone marrow samples, AFP mRNA was detectable in 5 of 11 (45%) cases, with 4 ag/100 fg to 23 ag/100 fg GAPDH (mean 9). However, AFP mRNA was also detectable in 3 of 18 (17%) control patients and in 2 of 26 (8%) healthy blood donors. Perioperative findings were highly variable. Conclusion: AFP mRNA is not a specific marker for circulating malignant hepatocytes. Whether definition of a cut-off level or the use of a multimarker-PCR will provide more useful data remains to be established.