Calcyphosine (CAPS), a
calcium-binding protein, has been identified as a potential diagnostic and prognostic
biomarker in several human
carcinomas. However, little is known about CAPS in
esophageal squamous cell carcinoma (ESCC). The present study aimed to investigate the expression levels of CAPS in ESCC tissues and evaluate its clinicopathological significance. Reverse transcription-quantitative polymerase chain reaction and immunohistochemical staining were conducted to detect the expression of CAPS in ESCC tissues and adjacent non-cancerous tissues. ESCC samples exhibited higher levels of CAPS
mRNA than paired non-cancerous samples (P=0.0015), and the
mRNA level of CAPS was positively associated with histological grade (P=0.0013) and
tumor invasion depth (P=0.0206). In addition, Kaplan-Meier survival analysis revealed that patients with high CAPS expression experienced significantly shorter 5-year overall survival times than those with low CAPS expression (P=0.0112). Multivariate analysis demonstrated that CAPS
protein expression was an independent prognostic
biomarker for patients with ESCC. In conclusion, the findings of the present study demonstrated that CAPS may represent a novel diagnostic
indicator and an independent prognostic
biomarker in ESCC.