Postoperative adjuvant transarterial chemoembolization for intrahepatic cholangiocarcinoma patients with microvascular invasion: a propensity score analysis

Background Microvascular invasion (MVI) is an independent risk factor associated with tumor recurrence and poor survival in patients with intrahepatic cholangiocarcinoma (ICC) after partial hepatectomy (PH). The potential impact of adjuvant TACE on the prognosis of patients with ICC involving MVI (ICC-MVI) remains uncertain. Our aim was to investigate the effectiveness of postoperative adjuvant transarterial chemoembolization (TACE) on ICC involving MVI. Methods Multicentric data consisted of 223 patients who underwent curative-intent PH for ICC-MVI from 2002-2015 were retrospectively analyzed. The impact of adjuvant TACE was evaluated using inverse probability of treatment weighting (IPTW) and propensity-score matched (PSM) analyses. Results No association between the TACE and the overall survival (OS) and recurrence rates was observed among the overall ICC-MVI patients. However, subgroup analyses revealed that adjuvant TACE favored OS (HR, 0.62; 95% CI, 0.39-0.99; P=0.047) and time to recurrence (TTR) (HR, 0.59; 95% CI, 0.36-0.97; P=0.037) among patients with elevated CA19-9 and those without lymphadenectomy (HR, 0.53; 95% CI, 0.30-0.93; P=0.027 for OS, and HR, 0.49; 95% CI, 0.28-0.87; P=0.015 for TTR, respectively). In the CA19-9 ≥39 U/L subgroup and Nx subgroup, adjuvant TACE was associated with higher 1-, 3-, and 5-year OS rates (P=0.033 and P=0.034, respectively) and lower corresponding recurrence rates (P=0.024 and P=0.023, respectively). Conclusions Among the ICC-MVI patients undergoing curative-intent PH, only those have elevated CA19-9 or who did not undergo lymphadenectomy might be suitable for adjuvant TACE.