Effect of infection on immunotherapy for gastrointestinal cancer: a narrative review.

Immunotherapy for gastrointestinal cancers has elicited considerable amount of attention as a viable therapeutic option for several cancer types. Gut microbiome as a whole plays a critical role in shaping immune responses and influencing cancer progression. Recent evidence suggests that (), may influence immunotherapy efficacy by modulating the tumor microenvironment. Infection with . is common as it affects approximately 50% of the global population and remains the leading risk factor for gastric cancer. Interestingly, recent clinical and preclinical data has associated with colorectal cancer carcinogenesis. Gut microbiome appears to be a modulator of the relationship between the immune system, gastrointestinal cancer development and existing therapies. Infection with may affect immunotherapy results in both gastroesophageal and colorectal cancer; favorable results were noticed in positive patients with gastric cancer, while in colorectal cancer patients the pathogen seemed to impede immunotherapy's action. This article aims to review current data on the role of in triggering gastric inflammation and cancer, as well as its potential involvement in colorectal cancer development. Additionally, it seeks to highlight the impact of infection on the response to immunotherapy in gastrointestinal cancers.