Copy number aberrations of genes related to extrohepatic metastasis-free survival after operation for hepatocellular carcinoma

Abstract

Objective: To investigate the molecular markers of copy number aberrations (CNAs) of genes related to extrohepatic metastasis-free survival after the operation for hepatocellular carcinoma (HCC). Methods: The CNA status of 20 candidate genes in 66 HCC samples was detected by microarray comparative genomic hybridization. The associations between gene CNAs and extrohepatic metastasis-free survival were evaluated using the Cox regression model, Log-rank test, and Kaplan-Meier survival analysis. Results: Multivariate Cox analysis revealed that the independent risk factors for metastasis-free survival were MDM4 gain (hazard ratio [HR] = 2.74, 95% confidence interval [CI] = 1.18-6.37, P < 0.05), APC loss (HR = 8.43, 95% CI = 2.48-28.66, P < 0.01), and BCL2L1 gain (HR = 3.45, 95% CI = 1.13-10.52, P < 0.05) and the independent protective factor was FBXW7 loss (HR = 0.32, 95% CI = 0.12-0.89, P < 0.05). By stepwise Cox regression analysis, three CNAs related to metastasis-free survival were screened out: MDM4 gain (HR = 2.71, 95% CI = 1.11-6.64, P < 0.05), APC loss (HR = 7.19, 95% CI = 1.88-27.60, P < 0.005), and FBXW7 loss (HR = 0.16, 95% CI = 0.05-0.46, P < 0.01). There were significant differences in metastasis-free survival rate between the HCC patients with FBXW7 loss and without MDM4 gain or APC loss, those with MDM4 gain and/or APC loss and without FBXW7 loss, and those with other CNA combinations (log-rank test, P < 0.01). Conclusion: MDM4 gain, APC loss, and FBXW7 loss are the independent prognostic factors for extrohepatic metastasis-free survival after the operation for HCC and can be used to predict the risk of extrohepatic metastasis after the operation for HCC.