Helicobacter pylori infection as a potential favorable factor for immune checkpoint inhibitor therapy for gastric cancer.

Gastric cancer (GC) has the third highest rate of cancer incidence and mortality worldwide. First-line immune checkpoint inhibitor (ICI) therapy for advanced GC led to landmark breakthroughs, but which GC patients are most likely to benefit from ICI therapy needs to be investigated in depth and identified via valuable biomarkers. In this letter, we describe superior outcomes in Asian patients than in North American and European patients treated with ICI therapy, and we speculate that positive H. pylori status may be a beneficial prognostic factor for ICI therapy in patients with GC. Many studies have revealed that H. pylori-activated immune responses improve prognosis in patients with GC via increased PD-L1 expression and CD3 ⁺ T cells. We propose that H. pylori status should be emphasized in ongoing or forthcoming ICI therapy trials to maximize the benefits of treatment for patients with advanced GC. Further research is required to better understand the mechanisms of inflammation and cancer progression.
(© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)