Abstract
OBJECTIVE: The aim of this study was to evaluate the prognostic value of a novel tumor marker index (TMI) based on preoperative serum levels of squamous cell carcinoma antigen (SCC) and cytokeratin 19 fragment (CYFRA 21-1) for patients with resectable esophageal squamous cell carcinoma (ESCC). METHODS: A total of 315 ESCC patients who had underwent curative surgery between 2008 and 2012 were retrospectively included in this study. The TMI was defined as the geometric mean of normalized SCC and CYFRA21-1 levels. Univariate and multivariate survival analyses were performed to confirm the clinical and prognostic significance of preoperative SCC and CYFRA 21-1 levels and TMI. RESULTS: Elevated preoperative SCC was associated with histological grade, pT status, lymph node status and TNM stage. Elevated preoperative CYFRA 21-1 was correlated with tumor size, lymph node status and TNM stage. The overall survival of patients with elevated SCC and CYFRA 21-1 levels was significantly poorer than that of patients with normal levels. Multivariate survival analysis identified that preoperative SCC (P= 0.353) and CYFRA 21-1 (P= 0.139) were not independent prognostic factors. The cut-off value of TMI based on SCC and CYFRA 21-1 was 0.531, and the patients were subdivided into high and low TMI groups. The 5-year survival rate of patients with high TMI was 30.9%, which was significantly lower than that of patients with low TMI (50.4%, P< 0.05). Multivariate analysis identified the TMI (HR 1.371; 95% CI 1.024-1.836; P= 0.034) as an independent prognostic factor. CONCLUSIONS: Elevated preoperative SCC and CYFRA 21-1 levels were associated with aggressive cancer behavior in ESCC. The TMI based on preoperative SCC and CYFRA 21-1 might serve as a novel marker that can be used to predict the prognosis of ESCC patients.