Kaplan-Meier estimation of disease-free survival (DFS) for colon adenocarcinoma patients. A-C, DFS in patients (n = 170) according to SNCG level, CEA level, and combined CEA with SNCG. Patients with SNCG positive (A), CEA positive (B), either SNCG or CEA positive (C) all showed significantly poorer DFS rates than those with the corresponding negative factors (P = 0.001, <0.0001, <0.0001, respectively by Log Rank (Mantel Cox) test). D, DFS in 97 patients with normal preoperative serum CEA level. SNCG-positive patients had a significantly poorer survival rate than those SNCG-negative patients (P = 0.002 by Log Rank (Mantel Cox) test). Numbers in the graph indicate percentages of DFS at 5 year, respectively.