Serum level of interleukin‐35 as a potential prognostic factor for gastric cancer

Abstract

Interleukin-35 (IL-35), a novel anti-inflammatory cytokine, has recently been implicated in tumor development, progression, and survival. However, the relationship between serum IL-35 levels and gastric cancer (GC) is inconclusive. Here, we performed this study to clarify the role of serum level of IL-35 in GC patients. We enrolled 180 GC patients and 170 healthy controls and used enzyme-linked immunosorbent assay to detect serum IL-35 levels. The clinical relevance between IL-35 and clinical pathology parameters was assessed. Univariate and multivariate logistic regressions were used to determine the feasibility of IL-35 as a clinical biomarker. We observed that serum IL-35 levels were significantly higher in GC patients (17.559 ± 13.266 pg/mL) than in healthy controls (8.077 ±3.801 pg/mL, P<.001). High serum IL-35 levels were significantly associated with clinical stage (P=.048) and Helicobacter pylori (HP) infection (P<.001). The Kaplan-Meier survival analysis indicated that patients in the high-IL-35 group had poor overall survival (OS) and progression-free survival (PFS) (median OS: 26.0vs 36.0 months, P<.001; median PFS: 18.0vs.26.0 months, P=.044). Multivariate analyses demonstrated that serum IL-35 was an independent prognostic factor for GC (OS: hazard ratio [HR]=1.031 [95% CI, 1.017-1.045], P<.001; PFS: HR=1.029 [95% CI, 1.015-1.043], P<.001). High serum IL-35 levels are associated with poor disease prognosis in GC patients, and it may be become a new and promising biomarker for prognosis of gastric cancer.