The high stromal SPARC expression is independently associated with poor survival of patients with resected pancreatic ductal adenocarcinoma treated with adjuvant gemcitabine in combination with S-1 or adjuvant gemcitabine alone

Abstract

BackgroundAlthough postoperative adjuvant chemotherapy for pancreatic ductal adenocarcinoma (PDAC) improves survival, its efficacy varies among individuals. Identification of biomarkers that can predict the efficacy of adjuvant chemotherapy for PDAC is essential. ObjectivesTo investigate the predictive value of secreted protein acidic and rich in cysteine (SPARC) expression in patients with PDAC treated with adjuvant gemcitabine in combination with S-1 (adjuvant GS) or adjuvant gemcitabine alone (adjuvant G alone). MethodsStromal SPARC and cytoplasmic SPARC were examined immunohistochemically in 211 PDAC patients treated with adjuvant GS or G alone after resection. The association of SPARC expression with clinicopathological factors, disease-free survival (DFS) and overall survival (OS) were analyzed. ResultsIn multivariate analysis, borderline resectable with arterial contact (BR-A) (P = .002), higher preoperative CA 19-9 level (≥91 U/ml) (P = .005), moderately or poorly (P = .003), presence of lymph node metastasis (P = .012) and high stromal SPARC expression (P = .013) were independent predictors of poor DFS. Moreover, BR-A (P = .003), higher preoperative CA 19-9 level (≥91 U/ml) (P = .007) and high stromal SPARC expression (P < .001) were identified as independent predictors of poor OS. In contrast, cytoplasmic SPARC expression did not affect DFS and OS. ConclusionsHigh stromal SPARC expression was an independent predictor of poor DFS and OS in patients treated with adjuvant GS or G alone. Stromal SPARC expression could be a relevant biomarker for prediction of prognosis in PDAC patients after resection treated with adjuvant GS or G alone.