Investigating the prognostic value of a panel of biomarkers after curative intent resection of pancreatic ductal adenocarcinoma.
211 Background: Pancreatic adenocarcinoma (PDAC) is the fourth leading cause of cancer mortality in the United States. 80% of tumors are discovered with distant metastasis upon presentation. Of patients eligible for curative intent surgery, the 5-year survival rate is only 20%. Identification of a panel of biomarkers correlated with patient specific prognosis upon diagnosis can serve as a way to individualize treatment options. Methods: A retrospective cohort study analyzing pathology of patients who underwent curative intent surgery at our institution from 1998-2011 to identify whether the expression patterns of six biomarkers:S100P, Maspin, KOC, CEA, p53, and Ki-67 can be predicative of patient specific prognosis. Tissue microarrays of specimens were assessed by immunohistochemistry. Results: A total of 62 patients are included. Comparisons between groups on overall survival (OS) and progression free survival (PFS) are estimated using the Kaplan-Meier method and the log-rank test. Each biomarker was represented as low and high expression by categorizing the expression score at >4, based on intensity and extent of cells stained. 40 deaths occurred in the sample. Distant metastasis and differentiation (well/moderate vs. poor) were borderline related to OS (p=0.0120, p=0.0086). Interestingly, patients with a poor differentiation were less likely to die due to any cause (HR=0.41, 95% CI: 0.21, 0.82). 29 patients progressed in their disease. High/low KOC expression were significantly related to progression free survival (p=0.0556). Incorporating previously reported data on KOC, patients with a high KOC expression were more than 2 times more likely to progress compared to those with a low KOC expression (HR=2.04, 95% CI: 0.97, 4.29). Conclusions: In our study S100P, Maspin, CEA, p53 and Ki-67 expression patterns were not statistically significant in identifying PFS or OS in PDAC patients. However, our data is suggestive of KOC being a useful prognostic biomarker for identifying those patients with PDAC who have a high risk for early progression and distant metastasis. Larger studies are needed to determine whether KOC can be a therapeutic target in the treatment of pancreatic cancer.