High levels of autotaxin and lysophosphatidic acid predict poor outcome in treatment of resectable gastric carcinoma

Abstract

Background: Although early-stage gastric cancer is a candidate for curative surgical resection, the absence of specific early symptoms results in a late diagnosis and consequently most patients present advanced or metastatic disease. Identifying noveland tumor-specific biomarkers is needed to increase early detection and match patients to the appropriate treatment. The present study focused on the possible prognostic role of Ectonucleotide Pyrophosphatase/Phosphodiesterase 2 (ENPP2)/Autotaxin (ATX) and lysophosphatidic acid (LPA) in Gastro-Esophageal Adenocarcinoma (GEA). High levels of ATX/LPA are associated with several malignancies including gastrointestinal tumors.

Methods: Using a bioinformatics analysis, the incidence of ENPP2 mutations together with its expression in the tumor tissues and the correlation between the presence of mutations and the survival rate were examined in databases of GEA patients. Furthermore, circulating levels of ATX and LPA were studied retrospectively and longitudinally both in patients receiving frontal surgery and in patients receiving preoperative chemotherapy.

Results: Overall findings suggested that although ENPP2 mutations occur at low incidence, their presence was associated with a particular poor Overall Survival (OS). Furthermore, removal of the tumour by surgery resulted in a decrease in serum ATX and LPA levels within five days, regardless of any previous chemotherapy. Basal circulating ATX were associated with the aggressive diffuse GEA and could be considered of negative prognostic value, mainly in combination models with circulating Carcino-Embryonic Antigen (CEA).

Conclusions: Based on these observations, clinical trials with ATX-targeted drugs and standard chemotherapy regimens may benefit from selecting GEA patients based on their levels of ATX, LPA and CEA.

Keywords: Autotaxin; Circulating factors; ENPP2 mutations; Gastro-Esophageal Tumours.