Real-time quantification of AFP mRNA to assess hematogenous dissemination after transarterial chemoembolization of hepatocellular carcinoma

Abstract

Objective: To determine whether the number of hepatocytes containing AFP mRNA shed into the bloodstream during transarterial chemoembolization (TAE) affects the incidence and pattern of recurrence of hepatocellular carcinoma (HCC).

Patients and methods: We developed a Taqman procedure to quantify AFP mRNA prospectively in 52 consecutive patients before and after TAE. Results are expressed in hepatocytes /mL.

Results: Thirteen of the patients (24.5%) were positive for AFP mRNA (42 +/- 19 hepatocytes/mL) before TAE and 13 (24.5%) (80 +/- 32 hepatocytes/mL) after TAE; the difference was not significant. The presence of AFP mRNA in the bloodstream before TAE was associated with larger nodules (85.2 +/- 73.8 mm versus 34.8 +/- 26.1 mm; P = 0.006). Six of the patients were excluded from the analysis because they underwent curative surgery or were lost to follow-up. The circulating levels of AFP mRNA released in the 46 remaining patients after TAE did not affect metastasis-free survival. A significant number of extrahepatic metastases were found in patients exhibiting at least 1 AFP mRNA-positive blood sample either before or after TAE. However, the TAE procedure did not increase the risk of extrahepatic recurrences.

Conclusion: Cells containing AFP mRNA are inconsistently released into the circulation during TAE. The amount of these cells released does not affect the recurrence of HCC.

FIGURE 1. AFP mRNA standard curve obtained by real-time RT-PCR. Standard curve plotting log starting copy number versus Ct. Gray dots, data for standard curve point samples using fresh isolated human hepatocytes; small black dots, data for samples from unknown patients.

FIGURE 2. Kaplan-Meier curves for metastasis-free survival for the 2 groups of patients are shown: 1) patients without AFP mRNA and 2) patients positive for AFP mRNA after TAE.