LAUSR

Abstract Thermal ablation is an alternative treatment for colorectal cancer liver metastasis (CRLM). However, prognostic factors in patients with CRLM who have undergone microwave ablation (MWA) have not been clearly defined. Therefore, this study aimed to analyze the risk factors associated with early recurrence in patients with CRLM treated with MWA. Herein, we retrospectively analyzed data for 140 patients with CRLM who underwent MWA from 2013 to 2015 in our institution. Patients were grouped by median pretreatment carcinoembryonic antigen (CEA) level into the high CEA level (>3.7 ng/mL) group and low CEA level (⩽3.7 ng/mL) group. Variables that might affect overall survival were subjected to univariable and multivariable Cox regression analysis. Our results showed a median progression-free survival (PFS) and median liver progression-free survival (LPFS) of 9 and 11.5 months, respectively, for the 99 CRLM patients analyzed. Both the median PFS duration (7.5 vs. 12.0 months; hazard ratio [HR]: 1.852; 95% confidence interval [CI]: 1.131–3.034; P = .014) and LPFS duration (7.5 vs 14.0 months; HR: 2.117; 95% CI: 1.247–3.593; P = .005) were significantly shorter in the high CEA level group than in the low level group. In multivariable analysis, high CEA level, >3 tumors, and positive node status for the primary tumor were independent factors for PFS, with corrected HRs of 2.11 (95% CI: 1.257–3.555; P = .005), 2.450 (95% CI: 1.420–4.226; P = .001), and 2.265 (95% CI: 1.304–3.935; P = .004), respectively. However, age, tumor size, regional lymph node were not associated with LPFS. CEA level could be a valuable prognostic factor for early recurrence in patients with CRLM after MWA irrespective of the presence of early local recurrence in the liver or disease progression.