Neutrophil Extracellular DNA Traps as a Clinical Biomarker and Target for Improved Outcomes Following Radical Cystectomy

Abstract

Title: Neutrophil Extracellular DNA Traps in Patients with Muscle-Invasive Bladder Cancer Objectives Neutrophil extracellular DNA traps (NETs) are DNA scaffolding structures released by neutrophils in response to injury, stress and infection and have been implicated in cancer metastasis. We sought to determine if NETs are detectable in the plasma of patients with muscle-invasive bladder cancer before and after radical cystectomy (RC). We also explored whether higher NET levels are associated with infection and early recurrence, and if specialized immunonutrition (SIM) supplementation of L-arginine reduces NET formation. Methods In a pilot randomized clinical trial, 29 men consumed nutrition supplementation 5 days before and 5 days after radical cystectomy at Kansas Health System. The intervention group (n=14) took a SIM beverage containing L-arginine (Nestlé, Impact Advanced Recovery®). The control group (n=15) also received oral nutrition support (Nestlé, Boost Plus®). Blood samples were collected at baseline, intra-operatively, and post-operative days 2, 14, and 30. Neutrophil elastase was measured using sandwich ELISA analysis. Granulocyte-colony stimulating factor (G-CSF) and plasma IL-6 were measured using MILLIPLEX® map human cytokine kit 1. Results were analyzed using generalized linear models with repeated measures. Results Twenty-six of the 29 patients had enough plasma to evaluate for NETs. All samples analyzed had detectable levels of NETs. There were no significant differences between NET levels in those with clinically identified infection or 3-year cancer recurrence. G-CSF showed an inverse relationship with NET formation in both groups with lower plasma levels during periods of higher detectable NETs. We did not detect a significant difference in NETs between the intervention and the control groups. Conclusions In our study, NETs were detectable in patients with bladder cancer. NET levels were highly variable across participants at all time points. NET levels did not differ between patients receiving the SIM drink as compared to those receiving the control nutrition supplement. Future research should evaluate if NET formation is a risk factor for early recurrence in a larger, multi-site sample.