The effect of adjuvant therapy for patients with intrahepatic cholangiocarcinoma after surgical resection: A systematic review and meta-analysis

Backgroud: Resection is still the only potentially curative treatment for patients with intrahepatic cholangiocarcinoma (ICC), but the prognosis remains far from satisfactory. However, the benefit of adjuvant therapy (AT) remains controversial, although it has been conducted prevalently. Hence, a meta-analysis was warranted to evaluate the effect of AT for patients with ICC after resection. Patients and methods: PubMed, MedLine, Embase, the Cochrane Library, Web of Science were used to identify potentially eligible studies from Jan.1st 1990 to Aug. 31st 2019, investigating the effect of AT for patients with ICC after resection. Primary endpoint was overall survival (OS), and secondary endpoints was recurrence-free survival (RFS). Hazard ratio (HR) with 95% confidence interval (CI) was used to determine the effect size. Results: 22 studies with 10181 patients were enrolled in this meta-analysis, including 832 patients in the chemotherapy group, 309 patients in the transarterial chemoembolization (TACE) group, 1192 patients in the radiotherapy group, 235 patients in the chemoradiotherapy group, and 6424 patients in the non-AT group. The pooled HR for the OS rate and RFS rate in the AT group were 0.63 (95%CI 0.52~0.74), 0.74 (95%CI 0.58~0.90), compared with the non-AT group. Subgroup analysis showed that the pooled HR for the OS rate in the AT group compared with non-AT group were as follows: chemotherapy group was 0.57 (95%CI = 0.44~0.70), TACE group was 0.56 (95%CI = 0.31~0.82), radiotherapy group was 0.71 (95%CI = 0.39~1.03), chemoradiotherapy group was 0.73 (95%CI = 0.57~0.89), positive resection margin group was 0.60 (95%CI = 0.51~0.69), and lymph node metastasis (LNM) group was 0.67 (95%CI = 0.57~0.76). Conclusion: With the current data, we concluded that AT such as chemotherapy, TACE and chemoradiotherapy could benefit patients with ICC after resection, especially those with positive resection margin and LNM, but the conclusion needed to be furtherly confirmed.