CD117 expression in operable oesophageal squamous cell carcinomas predicts worse clinical outcome

Aims To investigate the aberrant expression of CD117 in oesophageal squamous cell carcinoma (SCC) and its prognostic significance. Methods and results Immunohistochemical staining for CD117 was performed on tissue microarray and routine tissue sections from 157 oesophageal SCC patients and 10 normal oesophageal epithelia adjacent to tumour. The positive rate of CD117 expression was 29.9% in oesophageal SCC tissues, whereas no CD117 expression was detected in the 10 normal oesophageal epithelia. CD117 expression was significantly associated with T stage (P<0.001), distant metastasis (P=0.015), lymph node metastasis (P=0.019), and clinical stage (P=0.021). Progression-free survival in the patients with CD117-positive tumours was shorter than that in the patients with CD117-negative tumours (P=0.010). In univariate analyses, CD117 expression was the most significant factor for overall survival of oesophageal SCC patients (P<0.001), followed by lymph node metastasis (P=0.001), T stage (P=0.002), clinical stage (P=0.006), distant metastasis (P=0.020), and histological grade (P=0.027). Multivariate analyses verified that CD117 expression was an independent prognostic marker for oesophageal SCC patients (P=0.002). In addition, CD117 expression predicted poorer survival in patients without distant metastases. Conclusions CD117 expression in operable oesophageal SCC may be a valuable prognostic marker, and detection of its expression in clinical samples may be useful in defining a subclass of oesophageal SCCs with extremely poor clinical outcome, which may require a specially targeted treatment modality.