Neutrophil extracellular traps (NETs) and thrombosis (Thr) in pancreaticobiliary cancer (PBC).

Abstract

e16230 Background: NETs are linked to tissue damage, Thr and cancer progression. Detection of NETs in pancreatic cancer (PC) tissue and NET products in plasma, such as citrullinated Histone 3 (cit-H3) and myeloperoxidase (MPO), can predict survival. A robust biomarker to identify PC patients that may benefit from prophylactic antithrombotic interventions is still lacking. We hypothesized that NET products can predict PC patients at risk of poor outcomes. Methods: Frozen plasma collected on diagnosis from a cohort of 117 patients with HPBC (69% with PC) with known tissue factor (TF) levels was analyzed for MPO and cit-H3 by ELISA. Plasma MPO is a marker of neutrophil degranulation while cit-H3 is a more specific marker of NETosis. Univariate association of clinical variables, TF, cit-H3, MPO with overall survival (OS) was performed. For multivariable analysis, Cox proportional hazards regression model and backward stepwise selection based on the Bayesian information criterion (BIC) were used. Results: We observed a strong correlation between MPO and cit-H3. MPO also correlated with TF. Only TF showed a trend with association with the risk of Thr (p=0.053). Results of the multivariable model for OS are presented in the table (all patients and stratified by Thr status). High absolute neutrophil count (ANC) predicted worse OS only in patients without Thr. Increased cit-H3 was associated with worse OS. Higher MPO predicted worse OS in stage IV patients, which is in contrast to their relationship in stage I-III patients, where increased MPO was associated with improved OS. This interaction effect is stronger in patients with thrombosis. Conclusions: Plasma cit-H3, a systemic marker of NETosis, was associated with worse OS in PBC. Significant MPO by stage interaction implies a differential association of MPO with the OS among patients in different cancer stages. The activation status of neutrophils, including degranulation and NETosis, may be an important predictive biomarker for OS in patients with HPBC with interactions with both stage and Thr. Prospective studies to confirm and extend our findings are ongoing.[Table: see text]