The significance of transarterial chemoembolization combined with systemic chemotherapy for patients with KRAS wild-type unresectable metachronous colorectal carcinoma with liver metastases

Purpose: The purpose of this study was to assess the survival benefits of transarterial chemoembolization (TACE) combined with systemic chemotherapy as the first-line treatment for metachronous unresectable colorectal carcinoma with liver metastases (CLMs) and to identify prognostic determinants. Patients and Methods: One hundred and fifty-four patients with KRAS wild-type metachronous unresectable CLMs were retrospectively collected from January 2006 to December 2014. Patients were divided into four groups according to treatment modality: 43 patients with chemotherapy alone (Group A), 39 patients with chemotherapy plus TACE (Group B), 38 patients with chemotherapy plus cetuximab (Group C), and 34 patients with chemotherapy plus TACE and cetuximab (Group D). We compared the rate of patients converted to resection for liver metastases (LMs), overall survival among these groups, and assessed prognostic factors. Results: The median interval time from resection of primary tumor to the diagnosis of CMLs was 12.0 months. The 1-, 3-, and 5-year survival rates and median survival time (MST) for all patients were 83.1%, 24.7%, 5.8%, and 22.9 months, respectively. Survival rates were significantly different in four groups at 1 year, 3 years, and 5 years with the MST of 17.5, 28.4, 18.9, and 30.3 months, respectively (P < 0.0001). The R0 resection rates for LMs were 7.0% in Group A, 30.8% in Group B, 10.5% in Group C, and 32.4% in Group D, which were statistically significantly different (P = 0.004). Univariate analysis revealed that posttreatment carcinoembryonic antigen serum level, tumor node (TN) stage, resection of LMs, tumor response, and treatment group were the significant prognostic factors. After adjusting the covariates in multivariate analysis, TN stage (hazard ratio [HR] = 1.394, 95% confidence interval [CI] = 1.027-1.893, P = 0.033), tumor response (HR = 2.901, 95% CI = 2.105-3.999, P < 0.0001), and treatment group (HR = 0.726, 95% CI = 0.594-0.887, P = 0.002) remained independent prognostic determinants. Conclusion: For patients with initially unresectable KRAS wild-type CLMs, chemotherapy plus TACE improved the resectability of LMs and survival compared with chemotherapy alone or chemotherapy plus cetuximab.