BACKGROUND: Colon cancer is the second most common cancer in males and fourth most common in females in Korea. The levels of serum fibrin-fibrinogen degradation products (FDP) are elevated in many malignancies due to haemostatic alterations resulting from carcinogenesis. We compared serum FDP with carcinoembryonic antigen (CEA) to assess whether FDP has a diagnostic value for colon cancer. METHODS: A total of 177 serum samples from 95 colon cancer patients and 82 healthy controls were provided by the Korea Cancer Center Hospital biobank. Serum FDP levels were measured using the DR-70 detection kits (AMDL, USA) and the levels of serum CEA were measured using the Roche E170 Analytics (Roche Diagnostics, Germany). RESULTS: The mean serum FDP and serum CEA levels were significantly higher in the cancer patient group (FDP, 1.65+/-1.44 microg/mL; range, 0.36 to 9.48; CEA, 99.99+/-321.74 ng/mL; range, 1.46 to 2,170.00) than in the control group (FDP, 0.58+/-0.46 microg/mL; range, 0.02 to 3.27, P<0.05; CEA, 1.66+/-1.18 ng/mL; range, 0.20 to 6.38, P<0.05). The receiver operating characteristic curve for FDP showed 80% clinical sensitivity and 83% specificity with an optimal cut-off of 0.81 microg/mL, while that for CEA exhibited 84% sensitivity and 94% specificity with a cut-off of 3.51 ng/mL. The area under the curve was 0.87 and 0.96 for serum FDP and CEA, respectively. A combination of the two markers showed 90% clinical sensitivity and 92% specificity for colon cancer. CONCLUSIONS: The diagnostic sensitivity for colon cancer was increased by using a combination of FDP and CEA.