Immune cell phenotype in endometrial cancer: from biological significance to clinical utility using Mendelian randomisation analysis.

Background: We investigated the relationship between immune cells and endometrial cancer by conducting a two-sample bidirectional Mendelian randomisation (MR) analysis.

Methods: MR uses genetic variation as an instrumental variable to study the causal effects of exposure on observed data outcomes. We conducted a dual-sample MR analysis to investigate the causal relationship between 731 immune cell phenotypes and endometrial cancer (EC). The weighted-median method and inverse variance weighted method MR were mainly used, and the p-value was corrected with the Benjamini-Hochberg procedure.

Results: The forward MR analysis revealed a causal relationship between EC and eight immune-cell phenotypes. The reverse MR analysis identified two immune-cell phenotypes with a potential causal effect on EC, with additional subtype-specific associations observed for endometrioid and non-endometrioid histology.

Conclusion: Our study demonstrated a causal relationship between immune cells and EC, thereby providing guidance for the development of future immunoregulatory therapeutic strategies.