Helicobacter pylori Infection Affects the Tumor Immune Microenvironment of Esophageal Cancer Patients.

Background/aim: We herein examined T cell immunity in esophageal cancer patients with and without Helicobacter pylori infection to establish a foundation for immunotherapeutic strategies targeting esophageal cancer in the presence of H. pylori infection.

Materials and methods: Twenty-six patients with esophageal squamous cell carcinoma between 2015 and 2017 were enrolled in the present study. Serum antibodies against H. pylori were measured. Fresh tumor tissues were obtained by endoscopic biopsy or from surgical resection. A cell suspension of these tissues was subjected to a flow cytometric analysis.

Results: Among the 26 patients analyzed, 10 (38.5%) were seropositive for H. pylori. The flow cytometric analysis of tumor-infiltrating lymphocytes revealed that the percentage of CD103⁺CD4⁺ T cells in esophageal tumors was significantly lower in H. pylori-positive patients than in H. pylori-negative patients (p=0.0105). Conversely, the percentage of CD45RA-CD25hi effector Treg cells in esophageal tumors was significantly higher in H. pylori-positive patients than in H. pylori-negative patients (p=0.0022), indicating an immunosuppressive tumor microenvironment in the former. Following neoadjuvant chemotherapy, the number of CD45RA-CD25hi effector Treg cells decreased (p=0.0248).

Conclusion: The tumor immune microenvironment of esophageal cancer patients with H. pylori infection exhibited an immunosuppressive phenotype. The targeting of Treg cells has potential in immunotherapy for this patient population.