Purpose: Gastric cancer (GC) is one of the most common malignancies worldwide. Although it has been strongly associated with immunopathology, IL-17 also has an important role in host defense so this makes it more important in GC, which is a microorganism-related cancer. The aim of this study was to determine the clinical significance of the serum levels of IL-17 in GC patients.
Methods: A total of 76 patients with GC and 30 healthy age- and sex-matched controls were enrolled in this study. Serum IL-17 levels were determined by the enzyme-linked immunosorbent assay method (ELISA) and these values were compared between groups.
Results: The median age at diagnosis was 60 years (21-84). Fifty-three (70%) patients were male and cardia was the most common tumor localization (n=40, 53%). Thirty-eight patients had metastasis (n=38, 50%) at presentation and liver was the most common organ with metastasis (n=17, 22%). Mean progression free survival (PFS) and overall survival (OS) of GC patients were 4.0 ± 0.9 months (95% CI: 2 - 6 months) and 14.6 ± 1.2 months (95% CI:12-17), respectively. 1-year OS rate was 52.8% (95% CI: 40.5-65.2). The median serum IL-17 levels of GC patients were significantly higher than of controls (9.04 vs. 8.07 pg/mL, p=0.01). There was no significant difference according to known disease-related clinicopathological and most of the laboratory parameters (p>0.05) but there was a positive relationship between CA-19.9 and IL-17 levels (p=0.04). Serum IL-17 levels had no significant impact on PFS, OS (p=0.51 and p=0.33) and also on response to chemotherapy (p>0.05).
Conclusion: While serum IL-17 levels were significantly higher in patients with GC compared to health subjects, it has no prognostic value on survival. Serum IL-17 levels may be a new candidate marker in the diagnosis of GC.