Effects and mechanisms of Helicobacter pylori on cancers development and immunotherapy

Tumor immunotherapy has been widely used in clinical treatment of various cancers. However, some patients of these cancers do not respond to immunotherapy effectively. And infection has been considered to be related to the efficacy of immunotherapy. This review aims to summarize the different effects and mechanisms of infection on immunotherapy in different kinds of cancers. We searched the relevant literature on and tumor immunotherapy, and summarized to form a review. Generally, infection plays a role in affecting kinds of cancers' development, besides gastric cancer. Current evidence suggests that infection may reduce the efficacy of immunotherapy for colorectal cancer, non-small cell lung cancer and melanoma, but due to the lack of sufficient evidence, more data is needed to prove that. While for gastric cancer, the effects remain controversial. The regulation effects and metabolisms involved in systematic related cancers should be paid attention to. Whether should be eradicated when immunotherapy performed may be a critical consideration for some kinds of tumors.