Serum soluble E‐cadherin is a potential prognostic marker in esophageal squamous cell carcinoma

E‐cadherin is a well‐documented tumor suppressor with downregulated expression in many cancer types. Upon proteolytic cleavage, a soluble form of 80‐kDa degradation fragment, known as soluble E‐cadherin (s‐Ecad), is present in circulation; its level in sera of cancer patients is significantly associated with metastasis, recurrence, and prognosis in some malignancies. The present study investigated the association of s‐Ecad with clinicopathological characteristics of patients with esophageal squamous cell carcinoma (ESCC) and its prognostic significance. A cohort of 97 patients who underwent surgery alone (n= 56) or neoadjuvant chemoradiation therapy and surgery (CRT) (n= 41) was recruited for this study. Serum samples were collected at operation (surgery group) and pre‐ and post‐CRT treatment (CRT group) for measurement of s‐Ecad protein by enzyme linked immunosorbent assay. Serum s‐Ecad levels were correlated with clinicopathological parameters as well as survival. Univariate analysis showed no significant relationship between serum s‐Ecad level and clinicopathological parameters for all sets of samples. Survival analysis showed that in patients who had surgical resection only, those with s‐Ecad levels equal to or below the median value survived significantly longer than those with levels above the median (median survival 25.6 vs. 14.1 months, P= 0.012). Multivariate analysis showed that pathological N stage, M stage, R category, and serum s‐Ecad level were significant independent prognostic factors for ESCC patients who underwent surgery only. The hazard ratio for s‐Ecad was 1.104 (95% CI: 1.026–1.187) and P= 0.008. Serum s‐Ecad was detected in ESCC patients and its potential as an independent prognostic marker requires further investigation.