Abstract
BACKGROUND: Current guidelines recommend hepatocellular carcinoma (HCC) screening in high-risk populations. However, the ideal HCC screening interval and screening modality have not been determined. This study aimed to compare the screening efficacy among different modalities with various intervals. METHODS: PubMed and other nine databases were searched through June 30, 2021. Binary outcomes were pooled using risk ratio (RR) with 95% confidence intervals (CIs). Survival rates were also pooled using RR with 95% CIs because most eligible studies only provided the number of survival patients instead of hazard ratio. RESULTS: In all, 13 studies were included. Two random controlled trials (RCTs) and six cohort studies compared screening intervals for ultrasonography (US) screening and found no significant differences between shorter (3- or 4-month) and longer (6- or 12-month) screening intervals in terms of early HCC proportion, HCC significant mortality, 1-year survival rate; screening at 6-month interval significantly increased the proportion of early HCC (RR = 1.17, 95% confidence interval [CI]: 1.08-1.26) and prolonged the 5-year survival rate (RR = 1.39, 95% CI: 1.07-1.82) relative to the 12-month interval results. Three other RCTs and two cohort studies compared different screening modalities in cirrhosis or chronic hepatitis B, which indicated no statistical differences in the proportion of early HCC (RR = 0.89, 95% CI: 0.40-1.96) and HCC mortality (RR = 0.69, 95% CI: 0.23-2.09) between the biannual US and annual computed tomography (CT screening). Biannual US screening showed a lower proportion of early HCC than biannual magnetic resonance imaging (MRI) (RR = 0.60, 95% CI: 0.37-0.97) and biannual US combined with annual CT (RR = 1.31, 95% CI: 1.13-1.51) screening. The proportion of early HCC in the contrast-enhanced US group was slightly higher than that in the B-mode US (RR = 1.08, 95% CI: 1.00-1.23) group. CONCLUSIONS: The evidence suggests that 6 months may be the best HCC screening interval for US screening. The effectiveness of CT and MRI is better than US during same screening intervals. However, MRI and CT are more expensive than US, and CT also can increase the risk of radiation exposure. The selection of CT or MRI instead of US should be carefully considered. REGISTRATION: No. CRD42020148258 at PROSPERO website ( https://www.crd.york.ac.uk/PROSPERO/ ).