Analysis of Factors Affecting Local Tumor Progression of Colorectal Cancer Liver Metastasis after Radiofrequency Ablation

Abstract

Purpose The purpose of this study was to evaluate the independent predictive factors for local tumor progression (LTP) of colorectal liver metastasis (CRLM) after radiofrequency ablation (RFA). Materials and Methods Patients with CRLM were included in the analysis if nodules were up to five in number, each nodule was ≤ 5 cm, and RFA was performed in our center from January 2006 to December 2015. Univariate and multivariate analyses to identify the predictors of LTP were performed by using a Cox proportional hazard model. Results Overall, 58 tumors from 38 patients were included in this study. LTP occurred in 14 tumors from 9 patients. The overall 1- and 3-year LTP rates were 23.5% and 29.4%, respectively. Multivariate analysis showed that tumor size > 2 cm and insufficient ablative margin were two independently significant adverse prognostic factors for LTP (p = 0.045 and 0.022, respectively). The 3-year LTP rates for 33 and 25 tumors with and without sufficient ablative margin were 4.5% and 61.2%, respectively. The difference was statistically significant (p < 0.001). The difference in the 3-year LTP rates according to the tumor size was not statistically significant (p = 0.791). Conclusion Insufficient ablative margin seems to be the most potent predictor of LTP after RFA of CRLM.

Keywords

• local neoplasm recurrence
• neoplasm metastasis
• radiofrequency thermal ablation
• colorectal neoplasm
• laparoscopy