Pretransplant absolute monocyte count in peripheral blood predicts posttransplant tumor prognosis in patients undergoing liver transplantation for hepatocellular carcinoma

BACKGROUND: Preoperative absolute monocyte count in peripheral blood (AMCPB) is closely associated with prognoses in not only various malignancies but also hepatocellular carcinoma (HCC). The purpose of this study was to evaluate whether pretransplant AMCPB predicts posttransplant outcomes in patients with HCC undergoing liver transplantation (LT). METHOD: We retrospectively analyzed relationships between clinicopathologic factors involving pretransplant AMCPB and tumor recurrence or survival in 256 patients who had undergone LT for HCC between January 2005 and April 2012. RESULTS: ROC curve analysis showed that AMCPB >200/mm(3) was a risk factor for tumor recurrence; 43 patients showed higher AMCPB (>200/mm3), whereas 213 showed lower AMCPB (<= 200/mm(3)) at the time of LT. On multivariate analysis, pretransplant high AMCPB, positive findings in pretransplant F-18-FDG PET/CT, pathological maximal tumor size >5 cm, intrahepatic metastasis, moderately or poorly differentiated tumor and microvascular invasion were independent factors affecting recurrence-free survival. When we performed subgroup analysis based on the Milan criteria, high AMCPB was an independent factor for predicting HCC recurrence in patients with tumor beyond the Milan criteria (P=0.004), and not for patients within the criteria. CONCLUSION: This study demonstrated that pretransplant AMCPB could predict tumor recurrence after LT for HCC, especially in patients with tumor beyond the Milan criteria.