Hepatic steatosis is associated with lower incidence of liver metastasis from colorectal cancer

Purpose Both hepatic steatosis (HS) and colorectal cancer (CRC) are conditions associated with metabolic syndrome. The liver is the most frequent site of distant metastasis of CRC; however, the impact of HS on the incidence of liver metastasis of CRC is not clearly defined. Then, the correlation with the presence or absence of HS was analyzed. Methods A total of 604 CRC patients receiving curative surgical resection who had a preoperative non-enhanced computed tomography (CT) were enrolled. The mean attenuation values (in Hounsfield units) of the liver and spleen were obtained on a plain CT slice, and the patients with liver–spleen attenuation ratio lower than 1.1 were objectively defined as HS. The clinicopathological features of these patients were analyzed, and the association between HS and the clinical features of CRC was examined. Results Sixty-three (10.4 %) among the 604 patients were diagnosed as HS. Recurrence-free survival (RFS) and hepatic RFS, but not extrahepatic RFS, were significantly higher in the group with HS ( p = 0.04 and p = 0.006). However, this effect was not evident in the group of patients with obesity, defined as body mass index > 25.0. Among the stage I~III cases, HS was significantly associated with lower hepatic, but not extrahepatic, RFS. Moreover, absence of HS was an independent risk factor for hepatic RFS ( p = 0.003). Conclusion Metastases of CRC are less frequent in fatty liver. Steatosis may be an unfavorable microenvironment for metastatic formation in the liver.