AFP mRNA detected in bone marrow by real-time quantitative RT-PCR analysis predicts survival and recurrence after curative hepatectomy for hepatocellular carcinoma

Abstract

Objective: To determine whether detection of hepatocellular carcinoma (HCC) cells by real-time quantitative RT-PCR targeting of alpha-fetoprotein mRNA (AFP mRNA) before or after curative hepatectomy predicts HCC recurrence and patient survival.

Summary background data: The presence of cancer cells in peripheral blood and/or bone marrow in patients with malignant disease has been reported to correlate with outcome.

Methods: Between July 2000 and June 2005, 136 consecutive HCC patients underwent primary curative hepatectomy. Bone marrow aspirated preoperatively, and peripheral blood samples collected before and after operation were subjected to real-time quantitative RT-PCR analysis using AFP mRNA as a target molecule. Median follow-up was 23 months (range, 6-54 months). Patient survival (PS), disease-free survival (DFS), and clinicopathologic features were compared between patients with positive and negative AFP mRNA.

Results: Twenty-four patients died (22 from HCC). HCC recurred in 66 patients (hepatic in 37 [56.1%]; hepatic and remote in 17 [25.8%], and remote alone in 12 [18.2%]). Bone marrow was positive for AFP mRNA in 38 patients (27.9%) and negative in 98 (72.1%). One- and 3-year PS was 96.6% and 91.4%, respectively, with negative AFP mRNA versus 86.2% and 55.5%, respectively, with positive AFP mRNA (P < 0.0001). One- and 3-year DFS were 73.2% and 44.8%, respectively, with negative AFP mRNA versus 54.5% and 25.8%, respectively, with positive AFP mRNA (P = 0.0399). Portal vascular invasion, tumor size, multiple tumors, and tumor differentiation correlated with inferior PS and DFS on univariate analysis. On multivariate analysis, positive AFP mRNA was the most important risk factor for PS (P = 0.001) and DFS (P = 0.0165). In addition, positive AFP mRNA in peripheral blood after operation tended to predict reduced DFS.

Conclusion: AFP mRNA in the bone marrow and systemic circulation during the perioperative period predicts patient survival and recurrence after curative hepatic resection for HCC.

FIGURE 1. The real-time amplification plots showed strong linear relationship between AFP mRNA quantity and the count of containing HCC cells. The sensitivity was determined theoretically at 1 AFP mRNA-positive cell in approximately to 10⁷ white blood cells from healthy donor.

FIGURE 2. The ratio of normal liver tissues was higher than that of HCC tissues. The range of the ratio of normal liver tissue was close but that of HCC tissues was widely, from zero to more than 15,000,000.

FIGURE 3. Survival rates and disease-free survival rates of negative AFP mRNA in bone marrow were higher than with positive AFP mRNA in bone marrow (P < 0.0001, P = 0.0399).

FIGURE 4. A, Survival rates and disease-free survival rates of negative AFP mRNA in preoperative peripheral blood tended to be higher than with positive AFP mRNA in bone marrow (P = 0.1205, P = 0.1035). B, Survival rates and disease-free survival rates of negative AFP mRNA in postoperative peripheral blood tended to be higher than with positive AFP mRNA in bone marrow (P = 0.1710, P = 0.5784).