Glypican-3 versus alpha-fetoprotein as a biomarker for hepatocellular carcinoma: a diagnostic meta-analysis

Objective: To assess the diagnostic accuracy of serum GPC3 versus alpha-fetoprotein (AFP) for HCC by using the method of system review. Methods: PubMed and EMBASE were searched from its inception to 20, April 2014 for studies that compared diagnostic accuracy of serum GPC3 with AFP for HCC. Sensitivity, specificity and other measures were pooled using random-effects models. Summary receiver operating characteristic curve analysis was used to summarize the overall test performance. Results: Fourteen studies were included in this meta-analysis. Summary estimates for serum GPC3 and AFP in diagnosing HCC were as follows: sensitivity, 69% (95% confidence interval (CI), 56-80%) vs. 60% (95% CI, 50-69%); specificity, 91% (95% CI, 76-97%) vs. 92% (95% CI, 84-98%); diagnostic odds ratio (DOR), 22 (95% CI, 6-83) vs. 18 (95% CI, 8-41); and area under sROC, 0.85 (95% CI, 0.81-0.88) vs. 0.80 (95% CI, 0.76-0.83). The pooled sensitivity and specificity for (GPC3+ AFP) and AFP were: sensitivity 80% (95% CI, 75-85%) vs. 64% (95% CI, 53-73%) and specificity 86% (95% CI, 74-93%) vs. 96% (95% CI, 86-99%). A significant heterogeneity was found among the ten studies, and meta-regression and subgroup meta-analysis suggested that race and assay type were probably responsible for the heterogeneity. Conclusions: Serum GPC3 may be a promising diagnostic marker of HCC and it was helpful for early detection of primary hepatocellular carcinoma when combined with AFP. More studies for specific race of patients, and using certain methods for detecting GPC3 are required to further confirm the diagnostic value of GPC3 for HCC.