Lack of association between genetic polymorphisms in cytokine genes and tumor recurrence in patients with hepatocellular carcinoma undergoing transplantation

Abstract

Recurrence of hepatocellular carcinoma (HCC) after liver transplantation (LT) remains one of the most common causes of poor long-term survival. However, the host genetic factors affecting increased risk of tumor recurrence after transplantation have not been thoroughly elucidated. The present study was designed to investigate the association of cytokine gene polymorphisms with the risk of tumor recurrence in LT patients for HCC. Eleven single-nucleotide polymorphisms within the promoter regions of 7 cytokine genes, i.e., the IL-1 family (IL-1alpha and IL-1beta), IL-6, IL-8, IL-10, TNF-alpha, and TGF-beta1, were genotyped in 93 HCC patients treated with LT using DNA sequencing. The association between these polymorphisms and the risk of tumor recurrence was evaluated while controlling confounding clinical variables. The genotype frequency of IL-10 -1082 A/G in patients with and without recurrence of HCC was AA 83.3%, GA 16.7% and AA 97.6%, GA 2.4%, respectively. The association between IL-10 -1082 GA and recurrence was significant (P=0.033). No other single-nucleotide polymorphism in the cytokine gene was found to be associated with recurrence. Kaplan-Meier survival curves showed that the homozygous AA patients had a significantly longer mean recurrence-free survival than heterozygous GA patients (23.5 vs 5.7 months, P=0.001). However, multivariate analysis failed to reveal that the GA genotype of IL-10 -1082 A/G was an independent indicator of recurrence. This study suggests the lack of association of selected cytokine gene polymorphisms with HCC recurrence after LT in the Han Chinese population. The finding does not exclude the idea that other cytokine polymorphisms could act as candidate biomarkers of disease prognosis.