Systemic chemotherapy plus transarterial chemoembolization versus systemic chemotherapy alone for unresectable intrahepatic cholangiocarcinoma: a multicenter retrospective cohort study

Purpose Systemic chemotherapy (SYS) is the first-line treatment of unresectable intrahepatic cholangiocarcinoma (ICC). However, the survival benefit of SYS is still limited. This study compared the efficacy and safety of patients with unresectable ICC treated with transarterial chemoembolization (TACE) plus SYS to SYS alone. Material and methods The multicenter retrospective cohort study included patients aged >= 18 years old with pathologically diagnosed ICC. Patients with unmeasurable lesions, not receiving SYS treatment, Child-Pugh grade C, Eastern Cooperative Oncology Group performance status score of 3 or higher, prior liver resection, incomplete medical information, or discontinuation of the first SYS treatment were excluded. Data collection was mainly from the hospital system, and the survival outcome of patients was obtained through follow-up. Overall survival (OS) was estimated using the Kaplan-Meier method and compared using the log-rank test. Propensity score matching at a 1:1 ratio using the nearest neighbor matching algorithm was performed to reduce selection bias between the TACE plus SYS and SYS alone groups. The Cox proportional hazards model was used to identify prognostic factors associated with OS and to estimate their hazard ratios. Modified Response Evaluation Criteria in Solid Tumors criteria were utilized to evaluate the response of tumors to therapy. Results Between June 2016 and February 2023, 118 unresectable ICC patients from three hospitals were included in this study. Of them, 37 were in the TACE plus SYS group and 81 were in the SYS alone group. The median OS in the combination group was 11.3 months, longer than the 6.4 months in the SYS alone group (P = 0.011). A greater objective response rate (ORR) and disease control rate (DCR) were observed in the combination group than in the SYS alone group (ORR, 48.65 vs. 6.17%, P < 0.001; DCR, 89.19 vs. 62.96%, P = 0.004). There were 16 patients in each group after matching, and the matched results remained consistent regarding OS and tumor response. Adverse events (AEs) were similar in the two groups after matching. Conclusion Compared to SYS alone, the combination treatment of TACE plus SYS was more effective than SYS alone in improving OS, ORR, and DCR without any significant increase in AEs. TACE plus SYS may be a viable treatment option for patients with unresectable ICC.