Stromal secreted protein acidic and rich in cysteine expression: A potential target for improved prognosis in patients with pancreatic cancer

Abstract

BACKGROUND Pancreatic cancer tissues mainly consist of fibrotic and dense stroma, which limits their therapeutic efficacy. The stromal fibroblasts of pancreatic tumors frequently express the secreted protein acidic and rich in cysteine (SPARC). AIM To assess the impact of SPARC and its oncological relevance in patients undergoing pancreatic cancer resection. METHODS Ninety-one pancreatic ductal adenocarcinoma specimens were obtained from patients with curative resection between January 2009 and December 2015 as a retrospective study. SPARC expression patterns were analyzed using immunohistochemistry. Oncological outcomes were analyzed based on SPARC expression patterns. Oncological outcomes, based on SPARC expression, were analyzed in The Cancer Genome Atlas-Pancreatic Adenocarcinoma cohort (retrieved from a public database). RESULTS Patients with stromal SPARC expression (sSPARC+) had poorer overall survival than that in those without it (sSPARC-) (P = 0.035). However, among patients who received adjuvant treatment, no difference was observed in survival between the sSPARC+ and the sSPARC- groups (P = 0.14). In The Cancer Genome Atlas-Pancreatic Adenocarcinoma samples, the high SPARC expression group exhibited noticeably lower overall survival than that in the low expression group (cutoff: 14.1295, P = 0.0222). Furthermore, SPARC expression was strongly correlated with the percentage the CD10+ stromal component (R2 = 0.804, P < 0.001). CONCLUSION Adjuvant chemotherapy improves survivals in sSPARC+ pancreatic cancer patients, indicating suggesting sSPARC expression as a prognostic biomarker and potential indicator for neoadjuvant treatment planning.