Impact of helicobacter pylori infection status on outcomes among patients with gastric cancer treated with immune checkpoint inhibitors: A systematic review and meta-analysis.

[BACKGROUND] Helicobacter pylori (H. pylori), a microaerophilic gram-negative bacterium, is one of the most common chronic bacterial infections in humans, affecting about 50 % of the global population. Recently, it has been proposed that H. pylori infection might impact the efficacy of immune checkpoint inhibitors (ICIs), which are used in the treatment of various cancers, including gastric cancer (GC). However, the impact of H. pylori infection on clinical outcomes in patients with GC treated with ICIs is not yet fully elucidated.

[OBJECTIVES] Evaluating the impact of H. pylori infection status on overall survival (OS) and progression-free survival (PFS) on GC treated with ICIs.

[METHODS] A meticulous literature search was conducted across PubMed, EMBASE, and Web of Science databases, focusing on studies that compared the effect of H. pylori-positive status versus H. pylori-negative status on patients with GC undergoing ICI treatment. The Newcastle-Ottawa Scale was utilized for the risk of bias assessment of individual studies. For binary outcomes, we used hazard ratios (HRs) or odds ratios (OR) with 95 % confidence intervals (CI) to estimate the effect size.

[RESULTS] In total, 3 studies were included, involving 928 patients, of which 396 had H. pylori-positive status. Analysis showed that: PFS was prolonged but not statistically significant in H. pylori-negative patients (HR: 1.11; 95 % CI:0.94-1.31; p = 0.17), OS was significantly prolonged in H. pylori-negative patients (HR: 1.25; 95 % CI: 1.05-1.50; p=0.012), and the H. pylori-negative group had a significant clinical response compared with the H. pylori-positive group (OR: 0.40; 95 % CI: 0.28-0.57; p < 0.000001).

[CONCLUSION] In this systematic review and meta-analysis, the status of H. pylori provides a perspective to reshape ICI treatment paradigms and advocates for early eradication treatment of this bacterium.