Phosph-Akt1 expression is associated with a favourable prognosis in pancreatic cancer

Abstract

Introduction: Akt, a serine/threonine protein kinase, mediates growth factor-associated cell survival. In several human cancers, including pancreatic cancer, constitutive activation of Akt (phosphorylated Akt, p-Akt) has been observed and may be associated with chemotherapy and radiotherapy resistance. However, there are contradictory viewpoints in p-Akt in pancreatic cancer on prognosis, and the clinical relevance of p-Akt in pancreatic cancer is not well understood. This study aims to investigate the expressions and relevance of Akt and p-Akt1 in pancreatic cancer tissues and their clinical significance. Materials and Methods: The expressions of Akt and p-Akt in 74 surgically resected paraffin-embedded pancreatic ductal adenocarcinoma samples and 10 normal pancreatic tissue samples were examined by immunohistochemistry. The associations of their expression with clinicopathological and survival data were analysed. Results: The positive expression rate of Akt and p-Akt1 were 87.8% and 83.8%, respectively, which were remarkably higher then those in normal pancreatic tissue (P <0.05). There was a positive correlation between the expression of Akt and p-Akt1. High p-Akt1 expression correlated with lower T stage (P = 0.004), while Akt was not associated with any clinicopathologic variables. Kaplan-Meier survival analysis revealed that higher expression of Akt, p-Akt1 were respectively correlated with favourable prognosis (16.0[4.7-27.3] vs 9.3[9.0-9.6] months, P = 0.007, and 23.0[12.2-33.8] vs 11.1[7.5-14.7] months, P = 0.004, respectively). Multivariate analysis identified p-Akt1 as a significant independent favourable prognostic factor (HR=0.421, P = 0.010). Conclusions: These results suggest that high p-Akt1 expression may be a favourable prognostic factor in pancreatic cancer.