Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is known to be associated with an increased risk of colorectal cancer (CRC). However, the relationship between NAFLD and the prognosis of CRC remains unclear. The primary objective of this study was to evaluate the overall survival (OS) and disease-free survival (DFS) rates in patients with CRC and the secondary objective was to compare clinicopathologic variables which were stratified by NAFLD. We performed a large cohort study of 1314 patients who were first diagnosed with CRC between January 2006 and April 2011. Postoperative follow-up data were collected from out-patient medical records, telephone consultations, and social security death indices. The Kaplan–Meier method was used to calculate the cumulative Ming-Hua Zheng The mean follow-up time was 52.7 25.3 months. Upon baseline comparison, the NAFLD group had significantly higher values of body mass index, triglycerides, and uric acid and significantly lower values of high-density lipoprotein, compared with the non-NAFLD group (P< 0.05 for all). There were no significant differences between the 2 groups with regard to tumor location, TNM staging, tumor differentiation, carcinoembryonic antigen, and vascular invasion. The cumulative 1-, 3-, and 5-year OS rates were 96.1%, 85.2%, and 80.6%, respectively, in the NAFLD group, which were statistically significantly higher than the OS rates of 91.6%, 76.2%, and 67.8%, respectively, in the non-NAFLD group (P1⁄4 0.075, P1⁄4 0.002, P1⁄4 0.030, respectively). There was no difference in DFS rates between the CRC patients with and without NAFLD (P1⁄4 0.267). Multivariate analysis showed that the presence of NAFLD was an independent negative risk factor for OS after adjusting for clinicopathologic covariates (hazard ratio1⁄4 0.593; 95% confidence interval 0.442, 0.921; P1⁄4 0.020), but not for DFS (P1⁄4 0.270). NAFLD may play a protective role in OS for CRC patients. Further studies are needed to elucidate the molecular mechanisms of putative protective effects in CRC patients with NAFLD. (Medicine 94(5):e479) Abbreviations: ALT = alanine aminotransferase, AST = aspartate aminotransferase, BMI = body mass index, CEA = carcinoembryonie antigen, CRC = colorectal cancer, CI = confidence interval, DM = diabetes mellitus, DFS = disease-free survival, HDL = high-density lipoprotein, HR = hazard ratio, IGF = insulin-like growth factor, LDL = low-density lipoprotein, NAFLD = nonalcoholic fatty liver disease, OS = overall survival. INTRODUCTION C olorectal cancer (CRC) is one of the most common cancers in the world and >1.2 million new cases are diagnosed each year. It is also the second leading cause of cancer mortality. It has been confirmed that most cases of CRC develop slowly over >10 years through the adenoma-carcinoma sequence. In China, the incidence and mortality from CRC have substantially increased at a higher rate in urban rather than rural areas over the past several decades. Changes in dietary patterns and physical activity may contribute to the increasing risk of CRC. Other risk factors for the development of CRC, which include family history of the disease, inflammatory bowel disease, smoking, excessive alcohol consumption, obesity, and diabetes mellitus (DM), have all been proven to evelopment of CRC. Therefore, it is sk factors, which may be associated with atients with CRC. www.md-journal.com | 1 Nonalcoholic fatty liver disease (NAFLD) is a clinical syndrome characterized by predominant macrovesicular steatosis of the liver. It is now recognized to be the most common chronic liver disease worldwide, affecting up to 20% to 40% of the population. The common most risk factors for acquiring NAFLD are obesity, DM, and hyperlipidaemia, which have been reported as predictable risks for CRC. Recently, several cross-sectional studies have been conducted to understand the potential association of NAFLD with an increased rate of colorectal adenomas and cancer. Our previous study further confirmed that NAFLD is an independent risk factor for CRC, even after adjusting for metabolic and other demographic factors. To date, there have been few studies investigating the potential impact of NAFLD on the prognosis of patients with CRC. Recently, one study found that the presence of NAFLD showed a favorable trend on survival rates in CRC patients, although the data did not reach statistical significance (P1⁄4 0.079), perhaps in part due to the small number of patients (227 patients) and poor statistical power. Therefore, we aimed to design a large and more statistically robust cohort study to investigate the impact of NAFLD on the prognosis of patients with CRC. MATERIALS AND METHODS