Expression of stem cell markers in pancreatic ductal adenocarcinoma and clinical relevance.

Abstract

e15058 Background: Emerging evidence has suggested that malignant tumors are heterogeneous and that are composed of a small subset of distinct cancer cells (usually defined by cell surface marker expression) that are responsible for tumor initiation and propagation, termed cancer stem cells. These cancer stem cells (CSCs), or tumor-initiating cells (TICs), exhibit properties of normal stem cells and are associated with resistance to current therapies. It was found that human pancreatic cancer has shown a population of cancer stem cells that have aberrantly activated developmental signaling pathways, are resistant to standard chemotherapy and radiation, and have up-regulated signaling cascades that are integral for tumor metastasis. The aim of our study is to investigate the prognostic implication of cancer stem cell markers in pancreatic ductal adenocarcinoma. Methods: In 43 histological samples of pancreatic ductal adenocarcinoma were performed molecular biology assessment of CD 24, CD44, CD133, CD166, OCT3/4, LGR5. Results: At univariate analysis patients with an overexpression of CD44, CD133, OCT3/4 showed a worse prognosis in terms of overall survival (respectively: p=0.031; p=0.014; p=0.001). At multivariate analysis OCT3/4 resulted to be independent factor influencing outcome (HR=0.23). Patients with overexpression of all factors seem to have a worse OS compared to patients expressing only two, one or none (8.6 vs. 15.6 vs. 18.0 vs. 59.9 mts; p=0.006). Conclusions: Our data suggest that the presence of cancer stem cells could be linked with tumor aggressiveness and patients’ survival. This finding could drive therapeutic decision towards less or more intensive treatment.