Transarterial Chemoembolization Followed by Radiofrequency Ablation for Hepatocellular Carcinoma: Impact of the Time Interval between the Two Treatments on Outcome

Purpose: To compare the efficacy of radiofrequency (RF) ablation after transarterial chemoembolization within or beyond 30 days for medium-large or multiple recurrent hepatocellular carcinomas (HCCs). Materials and Methods: In this single-center retrospective study conducted from 2007 through 2015, 135 patients with a single recurrent HCC (>3 cm) or multiple (2-5 tumors) recurrent HCCs underwent transarterial chemoembolization plus RF ablation. A total of 62 patients underwent RF ablation after transarterial chemoembolization within 30 days (sequential group) and 73 patients underwent RF ablation after transarterial chemoembolization beyond 30 days (delayed group). Outcomes of interests included overall survival (OS), progression-free survival (PFS), and complete response (CR) rate. Results: The median OS and PFS were 49.8 and 38.0 months for sequential group, and 31.0 and 11.6 months for the delayed group. The sequential group experienced significantly better OS (hazard ratio [HR]: 0.517; P=.002) and PFS (HR, 0.621; P=.021). Among patients with multiple tumors or a single tumor >5 cm, the sequential group still had significantly longer OS (P=.022; P=.018, respectively) and PFS (P=0.042; P=.036, respectively) than the delayed group, although no significant differences were observed among patients with solitary 3-to 5-cm tumors (P=.138; P=.803, respectively). The sequential group had a significantly better CR rate than the delayed group (85.4% vs. 68.5%, respectively; P=.035). Significant predictors of OS and PFS included maximum tumor size, number of tumors, and time interval between transarterial chemoembolization and RF ablation. Conclusions: Transarterial chemoembolization plus sequential RF ablation within 30 days was more effective for recurrent HCCs than transarterial chemoernbolization plus delayed RF ablation. The time interval within 30 days is required for treating large or multiple HCCs but may not be necessary for solitary medium-sized HCC.