en بیوشیمی Biochemistry پژوهشي Research <strong>Background:</strong> Currently, glycans, which are known as functional molecules in the biological system, are being under study as potential cancer markers. This study aimed to determine the level of serum L-fucose and sialic acid as the biomarkers in patients with colorectal cancer (CRC).<br> <strong>Materials and Methods:</strong> The patients with CRC (n=40, 20 men and 20 women) participated in the present study. The spectrophotometric method was used to measure the levels of L-fucose and sialic acid in the serum of the patients. SPSS (version 21) was used to analyze the obtained data. The results were expressed as mean &plusmn; SD.<br> <strong>Results</strong>: The mean &plusmn; SD L-fucose level in patients with CRC was 27.46 &plusmn; 4.8 ng/mL, which was more than this level in the healthy control group (18.64&plusmn;3.1 ng/mL). Also, the mean &plusmn; SD serum concentration of sialic acid in patients with CRC was 2.1 &plusmn; 0.41 ng/mL, which was more than the mean &plusmn; SD sialic acid level of 1.23&plusmn;0.21 ng/mL in the healthy controls.<br> <strong>Conclusion</strong>: Serum concentration of L-fucose and sialic acid increased significantly (P < 0.05) in patients with CRC compared with the healthy controls. We believe that determining serum L-fucose and sialic acid levels could be useful for the detection of CRC patients in the early stage.<br> &nbsp; Colorectal cancer, glycosylation, serum markers 147 152 http://rmm.mazums.ac.ir/browse.php?a_code=A-10-609-7&slc_lang=en&sid=1 Roya Abbasinatajomrani royaabbasin@gmail.com 10031947532846009238 10031947532846009238 No Department of Biology, Payame Noor University, Tehran, Iran Durdi Qujeq dqujeq@gmail.com 10031947532846009239 10031947532846009239 Yes Department of Clinical Biochemistry, Faculty of Medicine, Babol University of Medical Sciences, Babol, Iran Vahid Hosseini Dr.vahid47@gmail.com 10031947532846009240 10031947532846009240 No Gut and Liver Research Center, Mazandaran University of Medical Sciences, Sari, Iran Reza Hajihosseini hosseini@pnu.ac.ir 10031947532846009241 10031947532846009241 No Department of biochemistry, Payame Noor University, Tehran, Iran