Causal effects of hypertensive disorders of pregnancy on future gynecologic tumors: A two-sample Mendelian randomization study.

Background: Numerous observational studies have investigated the potential link between hypertensive disorders of pregnancy (HDPs) and the subsequent risks of gynecologic tumors, yet the findings have been inconsistent. In this study, we utilized Mendelian randomization (MR) approach to assess the influence of HDPs on the future risks of ovarian, cervical, endometrial, and breast cancer and uterine fibroids, controlling for confounding factors.

Methods: The genome-wide association studies (GWAS) summary data relevant to HDPs was obtained from the FinnGen databases (10,736 cases and 136,325 controls). Gynecologic tumor outcomes were extracted from the IEU Open GWAS project and UK Biobank (47,690 cases and 1, 092,073 controls). The inverse variance weighted (IVW) approach was selected as the principal method for MR analysis, supplemented by MR-Egger, weighted median, weighted model, simple model methods, MR pleiotropy residual sum and outlier (MR-PRESSO) test, and leave-one-out method. Multivariate MR (MVMR) analysis was conducted after adjusting systolic blood pressure (SBP), body mass index (BMI) and type 2 diabetes mellitus (T2DM).

Results: Our univariate MR analysis (UVMR) results revealed no significant relationship between HDPs and the risks of ovarian cancer (odds ratio [OR] = 0.924, p = 0.360), cervical cancer (OR = 1.230, p = 0.738), endometrial cancer (OR = 1.006, p = 0.949), uterine fibroids (OR = 1.155, p = 0.158), and breast cancer (OR = 0.792, p = 0.241) by IVW test. Similar results were observed in gestational hypertension and preeclampsia/eclampsia. Additionally, our study detected neither heterogeneity nor pleiotropy. MVMR analysis also provided no evidence of a causal association between HDPs and common gynecologic tumors after adjusting SBP, BMI, and T2DM.

Conclusion: We discovered no causal relationship between HDPs and ovarian, cervical, endometrial, breast cancer, and uterine fibroids in European populations. However, present analysis did not explore the effect of HDPs on the subtypes of gynecologic tumors across varied ethnic populations, which may require additional research.