Original article: Upregulation of caspase‐3 expression in esophageal cancer correlates with favorable prognosis: an immunohistochemical study from a high incidence area in northern China

Caspase‐3 plays an important role as the key effector during apoptosis, but there are very few studies of caspase‐3 in esophageal squamous cell carcinoma (ESCC). The purpose of this study was to investigate the expression and prognostic significance of caspase‐3 in ESCC from Linzhou City, a high incidence area in northern China. All 64 patients underwent esophagectomy for ESCC between January 2002 and December were enrolled in this study. Caspase‐3 expression was assessed by immunohistochemistry (IHC) in primary ESCC and paired normal esophageal epithelium. The positive rate of caspase‐3 expression was higher in ESCC than in normal esophageal epithelium (79.7% vs. 50.0%, Chi‐square = 12.372, P= 0.001). Caspase‐3 expression was correlated with tumor cell differentiation (Phi = 0.717, P < 0.001), tumor infiltration depth (Phi =?0.334, P= 0.008), and pathologic TNM (pTNM) staging (rs =?0.268, P= 0.032). Patients in caspase‐3 positive group had a significantly better 5‐year overall survival than those in the negative group (77.4% vs. 35.9%, χ²= 7.344, P= 0.007). Our results showed that caspase‐3 expression was upregulated in ESCC compared with normal esophageal epithelium in population of Chinese high incidence area, and patients with caspase‐3 positive expression had better prognosis. Therefore, caspase‐3 immunostaining could be a simple and useful tool for predicting survival in ESCC patients.