Background and purpose: Fatty acid synthase (FAS) is the sole protein in the human genome capable of intracellular synthesis of long-chain fatty acids. FAS overexpression is detected in various cancer tissues including colorectal cancer because of the increasing requirement of tumor for long-chain fatty acid. This study was to investigate the association between serum levels of FAS in patients with colorectal cancer and clinicopathological characteristics of colorectal cancer. Methods: A total of 60 patients who underwent radical surgical resection for colorectal cancer from Mar. 2013 to Mar. 2014 were selected as the study group

while 20 healthy volunteers were selected as the control group. The serum levels of FAS were measured by enzyme-linked immunosorbent assay (ELISA) methods. Differences of serum levels of FAS in patients with various clinicopathological characteristics of colorectal cancer were analyzed. Results: The serum levels of FAS in the study group were significantly different with those in the control group. Serum FAS levels of patients belonging to stage Ⅰ-Ⅱ

Ⅲ and Ⅳ were 13.24±11.43

24.20±11.87 and 35.44±12.18 mg/L

respectively

and were statistically different. Serum FAS levels of patients belonging to high

moderate and low differentiation were 16.46±10.58

20.38±11.87 and 25.84±10.88 mg/L

respectively

there were also statistically different. Conclusion: FAS may be involved in the development and progression of colon cancer.