Supplementary Material for: TACE for treatment-naive HCC has different treatment effects depending on central or peripheral tumor-location

Introduction: The purpose of this study was to evaluate the treatment efficacy of transcatheter arterial chemo-embolization (TACE) for treatment-naive hepatocellular carcinoma (HCC) according to tumor location and burden. Methods: Between 2010 and 2019, consecutive patients who underwent TACE as the first treatment were enrolled. Tumors were classified into two categories based on their location, as central or peripheral tumors. Tumors in the central zone, which is within 1 cm of the main trunk or the first branch of the portal vein, were classified as central tumors, while those located in the peripheral zone were classified as peripheral tumors. Patients were grouped according to the HCC location and up-to-7 criteria. Patients with central tumors were classified into the central arm and those with only peripheral tumors were classified into the peripheral arm. Patients within and beyond the up-to-7 criteria were classified into the up-to-7 in and up-to-7 out groups, respectively. Local recurrence-free survival (LRFS) and progression-free survival (PFS) were compared per-nodule (central tumor vs. peripheral tumor) and per-patient (central arm vs. peripheral arm), respectively. The prognostic factors of LRFS and PFS were analyzed by univariate and multivariate analyses. Results: A total of 174 treatment-naive patients with 352 HCCs were retrospectively enrolled. Ninety-six patients and 130 lesions were selected by propensity score matching. Median LRFS was longer for peripheral tumors than central tumors (not reached vs. 3.3 months, p<0.001). Median PFS was: 17.1 months (8.3-24.9) in the peripheral arm & up-to-7 in, 7.0 months (3.3-12.7) in the peripheral arm & up-to-7 out, 8.4 months (4.0-12.6) in the central arm & up-to-7 in, and 3.0 months (1.2-4.9) in the central arm & up-to-7 out groups. The peripheral arm & up-to-7 in group had significantly longer PFS than the other three groups (p=0.013, p=0.015, p<0.001, respectively). Multivariate analysis confirmed that the central zone and central arm were associated with high adjusted hazard ratios for tumor recurrence or death (2.87, p<0.001; 2.89, p<0.001, respectively). Conclusion: Treatment-naive HCCs in the peripheral zone had a longer LRFS and PFS following TACE compared to those in the central zone