Immune-Onco-Microbiome: A New Revolution for Gynecological Cancers

Abstract

Despite significant advances in understanding the pathogenetic mechanisms underlying gynaecological cancers, these cancers still remain widespread. Recent research points to a possible link between microbiota and cancer, and the most recent attention is focusing on the relationship between the microbiome, the immune system, and cancer. The microbiome diversity can affect carcinogenesis and the patient's immune response, modulating the inflammatory cascade and the severity of adverse events. In this review, we presented the recent evidence regarding microbiome alterations in patients with gynaecological tumours to understand if the link that exists between microbiome, immunity, and cancer can guide the prophylactic, diagnostic, and therapeutic management of gynaecological cancers.

Keywords: cancer immunotherapy; gynaecological cancers; gynaecological tumours; immunity; microbiome; microbiota.

Figure 1

Microbiome and immune system regulation: microbial homeostasis promotes barrier integrity. Bacterial dysbiosis induces mucosal barrier alterations with the release of inflammatory mediators and activation of immune cells.

Figure 2

Immune checkpoint inhibitors interact with microbiota and immune cells to enhance anti-tumour activity. Anti-programmed death-ligand 1(PD-L1) treatments, through the interaction with symbiotic bacteria, induce the activation of dendritic cells and promote the activation and function of T-helper cells. Anti-CTLA4 enhances the activity of dendritic cells and T-helper cells while suppressing T regulatory cell function. Solid arrows indicate the activating signal, while dashed arrows indicate the inhibitory signal.