Secreted protein acidic and rich in cysteine expression in human colorectal cancer predicts postoperative prognosis.

OBJECTIVE Secreted protein acidic and rich in cysteine (SPARC) is an extracellular matrix glycoprotein involved in cell proliferation, migration and angiogenesis. The aim of this study was to assess its expression in colorectal cancer, see whether and how it correlates with clinicopathological features, and evaluate its potential prognostic significance. PATIENTS AND METHODS SPARC expression was detected by microarrays containing 847 immunohistochemically stained specimens, and further correlated with the clinicopathological and prognostic data. The prognostic significance of its expression was assessed using Kaplan-Meier survival with log-rank tests. Multivariate regression utilizing Cox's proportional hazard model was used to evaluate prognostic factors. RESULTS SPARC expression in the normal colorectal mucosa and colorectal cancer tissue was significantly different (p < 0.001). Low SPARC expression was found to be associated with poor prognosis, and it was unfavorably correlated with overall survival and disease-free survival in colorectal cancer patients. In addition, SPARC expression in surrounding mesenchymal and stromal cells, bowel wall invasion, lymph node metastasis, and distant metastasis were independent prognostic factors for overall survival and disease-free survival. CONCLUSIONS Reduced expression of SPARC in colorectal cancer tissue is associated with poor prognosis and aggressive clinicopathological features. Therefore, SPARC expression could potentially be used as a prognostic predictor for colorectal cancer patients.