Locoregional therapy combined with systemic therapy (LRT plus ST) for unresectable and metastatic intrahepatic cholangiocarcinoma: a systematic review and meta-analysis

Background. The outcome of systemic therapy (ST) for unresectable and metastatic intrahepatic cholangiocarcinoma (iCCA) is poor. This study aims to further evaluate the efficacy and safety of locoregional therapy combined with systemic therapy (LRT + ST) compared with only ST in unresectable and metastatic iCCA by performing a systematic literature review and meta-analysis.Methods. A comprehensive search was performed in PubMed, Web of Science, EMBASE, and the Cochrane Library up to November 3, 2022. The primary outcome was overall survival (OS), and the secondary outcomes were progression-free survival (PFS), objective response rate (ORR), and adverse events (AEs).Results. Ten retrospective cohort studies with 3,791 unresectable or metastatic iCCA patients were enrolled in this study, including 1,120 who received ablation, arterially directed therapy (ADT), or external beam radiation therapy (EBRT) combined with ST. The meta-analysis showed that the LRT + ST group had a better OS (HR = 0.51; 95% CI =0.41-0.64; p value < 0.001), PFS (HR = 0.40, 95% CI = 0.22-0.71, p value = 0.002) and ORR (RR = 1.68; 95% CI = 1.17-2.42; p value = 0.005). Subgroup analysis showed that both ST combined with ADT (HR = 0.42, 95% CI = 0.31-0.56, p value < 0.001) and EBRT (HR = 0.67, 95% CI = 0.63-0.72, p value < 0.001) could improve OS. Neutropenia, thrombocytopenia, anemia, anorexia, and vomiting did not show significant differences between the groups (p value > 0.05).Conclusions. Compared with only ST, LRT + ST improved survival outcomes for unresectable and metastatic iCCA patients without increasing severe AEs, which can further provide a basis for guidelines.