The impact of hepatic fiblosis on the incidence of liver metastasis from colorectal cancer

529 Background: Non-alcoholic steatohepatitis (NASH) is closely associated with hepatic fibrosis (HF). The number of patients who have NASH is increasing by eating high-calorie diet. It remains unclear how much impact such NASH and HF on the development of liver metastasis by colorectal cancer (CRC). The objectives of this study is to clarify the influence of HF on metachronous liver-specific recurrence in colorectal cancer patients who underwent colorectal surgery with curative intent. Methods: Between 2000 and 2010, patients who underwent a curative surgical resection for CRC were included in this study. We evaluated the progression of HF by using non-alcoholic fatty liver disease fibrosis score (NFS) based on preoperative blood test result, age, BMI and DM. The patients with NFS higher than 0.676 were objectively defined as HF. The influence of HF on hepatic recurrence was assessed by survival analyses. Results: A total of 953 CRC patients were enrolled, comprised of 293 in stage I, 327 in stage II and 333 in stage III. The mean of NFS was 1.32±1.55, where the included patients were categorized into 77 HF and 876 non-HF. 5-year liver-specific disease-free survival rate in HF was significantly poorer than non-HF (HS 87.0% vs. non-HF 94.5%, log-rank p=0.009). Multivariate analysis demonstrated that HF significantly promoted liver-specific recurrence compared to non-HF (HR=2.16, 95% CI, 1.00 to 4.64; p=0.049). Conclusions: Hepatic fibrosis had a great impact on hepatic recurrence after curative surgical resection of CRCs. These findings indicated that HF might be a favorable microenvironment in developing colorectal liver metastasis. The evaluation of the degree of HF can be useful in selection of adjuvant chemotherapy and postoperative surveillance.