Prognostic significance of the number of hepatic lesions in multifocal intrahepatic cholangiocarcinoma after radical resection: an IPTW propensity-score analysis.

Background: Multifocal hepatic lesions represent a distinctive subgroup within intrahepatic cholangiocarcinoma(iCCA), the management of these patients remains controversial. This study aimed to compare the survival of intrahepatic cholangiocarcinoma (iCCA) with different numbers of hepatic lesions and select patients benefiting most from surgery in multifocal iCCA.

Methods: A cohort of 354 consecutive iCCA patients were included. Based on the number of hepatic lesions, patients were classified as follows: solitary tumors (type I), 2 or 3 hepatic lesions in the same-sided hepatic lobe (type II), and more than three hepatic lesions in the same-sided hepatic lobe (type III). Stabilized inverse probability treatment weighting (IPTW) was conducted for accurate prognosis comparisons. Furthermore, the long-term prognosis was compared between different American Joint Committee on Cancer.

Results: Among all patients, multifocal iCCA presented significantly worse overall survival (OS) and recurrence-free survival (RFS) than solitary tumor (p < 0.001 and p < 0.001), 11.9% (n = 42), and 14.4% (n = 51) patients were classified into type II, and type III, respectively. After IPTW, type II exhibited similar while type III exhibited worse RFS and OS to type I cohort (solitary tumors) (p < 0.001and p < 0.001). Multivariable Cox analysis also identified type III tumors as an independent risk factor for OS (HR 1.95, 95% CI:1.33-2.87, p < 0.001). Among AJCC stage II (T2N0M0) patients, multifocal iCCA presented significantly worse OS than solitary tumors (vascular invasion) (p = 0.018), and type II exhibited similar while type III exhibited worse OS than solitary tumors (p = 0.500 and p = 0.040). Compared with stage III patients, type II exhibited better while type III exhibited similar OS (p < 0.001 and p = 0.300).

Conclusions: Multifocal iCCA presented a significantly worse prognosis, the number of hepatic lesions significantly influenced the prognosis of multifocal iCCA. Patients with type II tumors may derive comparable oncological benefits from surgery compared with solitary tumors, radical surgery still be strongly recommended as the preferred treatment.