S100B Protein Expressions as an Independent Predictor of Early Relapse in UICC Stages II and III Colon Cancer Patients after Curative Resection

Abstract

S100 calcium-binding proteins such as S100B are elevated in primary malignant melanoma and are used as tumor markers for malignant melanoma and numerous other cancers. The purpose of this study was to identify the novel predictors of early relapse in UICC stages II and III colon cancer patients and thus to identify a subgroup of patients who are at high risk for postoperative early relapse. Clinicopathological factors and S100B expression by immunohistochemical staining were retrospectively analyzed in 357 postoperative UICC stages II and III colon cancer patients to determine the predictors of early relapse. Of 357 patients, 114 patients developed postoperative relapse during the follow-up period. Among 114 relapsed colon cancer patients, postoperative early relapse and non-early relapse were found in 56 patients (49.1%) and 58 patients (50.9%), respectively. Multivariate Cox proportional hazards analysis revealed that the presence of vascular invasion (P = .025; hazard ratio [HR], 5.532; 95% confidence interval [95% CI], 1.985-14.729), high postoperative CEA levels (P = .019; HR, 6.845; 95% CI, 2.393-15.256), and S100B overexpression (P < .001; HR, 26.250; 95% CI, 7.463-96.804) were demonstrated to be independent predictors of postoperative early relapse. Furthermore, postoperative relapsed colon cancer patients with S100B overexpression were demonstrated to have significantly lower overall survival rates than those without S100B overexpression (P < .001). This study suggests that S100B protein expression is a crucial predictor of early relapse in UICC stages II and III postoperative colon cancer patients and thus could help to define patients with this tumor entity who would benefit from enhanced follow-up and therapeutic program(s).