74P Genetic dissection of endocrine pathways underlying gynaecological cancer risk: Mendelian randomization and mediation analysis

Hormonal contraception and reproductive traits have long been linked to gynaecological malignancies, yet the endocrine pathways driving these associations remain incompletely understood. Given the heterogeneity of contraceptive exposures, examining endocrine traits that reflect key biological effects of hormonal exposure may offer a more interpretable framework for causal inference. We therefore investigated endocrine and reproductive determinants of ovarian and endometrial cancer using Mendelian randomization (MR).