Factors affecting survival in patients with isolated liver-metastatic colorectal cancer treated with local ablative or surgical treatments for liver metastasis.

Local treatments for isolated synchronous or metachronous liver metastases in colorectal cancer (CRC) have been shown to improve overall survival (OS). The aim of this study was to investigate the factors affecting OS in CRC patients with isolated liver metastasis in whom the primary tumor and corresponding liver metastasis were treated with curative intent using local ablative or surgical methods. A total 47 surgical operated CRC patients presenting with an initial or subsequent isolated liver metastasis, who were treated with local surgical or ablative treatment for liver metastasis with curative intent, were enrolled in this study between 2007 and 2017. The possible factors affecting OS were analyzed. Of the 47 patients, 35 (74.5%) were male. The median age was 61 (25 - 80) years. Thirty-four (72.3%) patients underwent liver metastasectomy, while 13 (27.7%) patients were treated with non-surgical local ablative therapies (NSLAT) for liver metastasis. Median OS (mOS) could not be reached in patients who underwent metastasectomy at the time of diagnosis compared to 55 months in those undergoing metastasectomy following a chemotherapy period (p = 0.03). Patients treated with NSLAT had a mOS of 60 months compared to ''not reached'' in those who underwent liver metastasectomy (p = 0.45). mOS was higher in patients with pT4 stage vs. with <pT4 stages (28 months vs. not reached, p = 0.02, respectively). Multivariate regression analysis revealed that undergoing liver metastasectomy at the time of diagnosis (HR 0.10; 95%Cl: 0.01 - 0.82) and pT4 stage (HR 4.365; 95%Cl: 1.27 - 14.98) were the most important independent factors affecting OS. This study demonstrated that CRC patients with isolated liver metastasis, <pT4 stage and curative liver metastasectomy achieved the best survival outcomes.