Clinicopathological significance of ASC amino acid transporter-2 expression in pancreatic ductal carcinoma

Aims: ASC amino acid transporter-2 (ASCT2) is highly expressed in cancer cells. However, the clinicopathological significance of ASCT2 expression in pancreatic cancer remains unclear. The aim of this study was to investigate the clinical significance of ASCT2 expression in pancreatic cancer. Methods and results: Ninety-seven patients with surgically resected pancreatic ductal adenocarcinoma were evaluated. Tumour sections were stained by immunohistochemistry for ASCT2, Ki67, CD34 (to determine microvessel density), phospho- AKT (p-AKT) and phospho-mammalian target of rapamycin (p-mTOR) expression. ASCT2 was expressed in 54% (52/97) of tumours. Statistically significant differences in patient age, T stage, N stage, lymphatic permeation, vascular invasion, Ki67, and CD34 and p-mTOR expression were observed between tumours with and without ASCT2 expression. Multivariate analysis confirmed that vascular invasion, ASCT2 expression and Ki67 expression were independent predictive factors for a poorer prognosis. Conclusions: ASCT2 expression plays an important role in tumour cell growth, and is a promising pathological marker for predicting a worse outcome in pancreatic cancer.