Correlation between secreted protein acidic and rich in cysteine protein expression and the prognosis of postoperative patients exhibiting esophageal squamous cell carcinoma

The aim of the present study was to investigate the association between the expression level of secreted protein acidic and rich in cysteine (SPARC) and the prognosis of post-operative patients with esophageal squamous cell carcinoma (ESCC). The expression level of SPARC was detected in the 89 ESCC tissue cases and 100 healthy esophageal mucosa cases, which served as the controls. Immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR) were employed to evaluate the SPARC expression in cases with ESCC. RT-PCR demonstrated that the positive rates of SPARC mRNA expression in ESCC were 71.91% (64/89). The positive rates of normal esophageal mucosa mRNA expression were 15.00% (15/100), which were significantly lower than that in the ESCC tissue samples. The difference was statistically significant (P<0.001). Immunohistochemical staining indicated that the positive expression rate of SPARC protein in the ESCC tissue samples was significantly higher than that in the esophageal mucosa tissue samples (65.17 vs. 8.00%; P<0.001). The expression of SPARC protein was negatively correlated with lymph node metastasis (P<0.05), which was not associated with the pathologic gross morphology, tumor differentiation degree or other clinical features. The survival of patients with ESCC was not associated with the expression level of SPARC protein (P>0.05), but was associated with the tumor location (P<0.05), differentiation (P<0.001) and staging (P<0.05). Thus, SPARC mRNA and protein were highly expressed in ESCC, and negatively correlated with lymph node metastasis, which was not associated with postoperative survival of ESCC patients. Thus, detection of SPARC mRNA and protein expression levels may facilitate early diagnosis and prognosis assessment of ESCC.