Combined detection of insulin-like growth factor-binding protein 7 promoter methylation improves the diagnostic efficacy of AFP in hepatitis B virus-associated hepatocellular carcinoma

This study quantitatively assessed serum insulin-like growth factor-binding protein 7 (IGFBP7) promoter methylation in hepatocellular carcinoma (HCC), and explored its clinical value. A total of 80 patients with hepatitis B virus-associated HCC, 35 patients with chronic hepatitis B (CHB), and 20 healthy controls (HC) were enrolled. MethyLight was used to quantitatively assess the methylation levels of serum IGFBP7 promoter. A logistic regression model was established for the combined evaluation of AFP and serum IGFBP7 promoter methylation. The results showed that mean methylation levels of serum IGFBP7 promoter were significantly higher in HCC (5.33%, interquartile range [IQR] 1.14-15.70%) patients than in individuals with CHB (1.54%, IQR 0.64-2.45%; P < 0.01) and HC (0.63%, IQR 0.22-0.98%; P < 0.01). In HCC subgroups, patients with vascular invasion, tumor size >3 cm and advanced tumor node metastasis (TNM) showed higher methylation levels compared with the remaining groups (P < 0.05). Compared with AFP alone, combined determination based on logistic regression analysis significantly improved the area under the receiver operating characteristic (ROC) curve (AUC) (0.759 vs 0.623, P < 0.05). In addition, the Youden index was increased from 5.71%, 11.25% and 15.18%, when considering AFP alone at cut-off values of 20, 200, and 400 ng/ml, respectively, to 45.71% with IGFBP7 promoter methylation taken into consideration (all P < 0.05). These results suggested that combined quantitative measurement of serum IGFBP7 promoter methylation could enhance the diagnostic ability of AFP in distinguishing hepatitis B virus-associated HCC from CHB.