Hypertensive diseases of pregnancy and risk of breast cancer in the Black Women's Health Study

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.

A common IGF1R gene variant predicts later life breast cancer risk in women with preeclampsia

PURPOSE

Preeclampsia has been inconsistently associated with altered later life risk of cancer. This study utilizes the Nurses' Health Study 2 (NHS2) to determine if the future risk of breast and non-breast cancers in women who experience preeclampsia is modified by carrying a protective variant of rs2016347, a functional insulin-like growth factor receptor-1 (IGF1R) single nucleotide polymorphism.

METHODS

This retrospective cohort study completed within the NHS2 evaluated participants enrolled in 1989 and followed them through 2015, with a study population of 86,751 after exclusions. Cox proportional hazards models both with and without the impact of rs2016347 genotype were used to assess the risk of invasive breast cancer, hormone receptor-positive (HR+) breast cancer, and non-breast cancers.

RESULTS

Women with preeclampsia had no change in risk of all breast, HR+ breast, or non-breast cancers when not considering genotype. However, women carrying at least one T allele of rs2016347 had a lower risk of HR+ breast cancer, HR 0.67, 95% CI: 0.47-0.97, P = 0.04, with interaction term P = 0.06. For non-breast cancers as a group, women carrying a T allele had an HR 0.76, 95% CI: 0.53-1.08, P = 0.12, with interaction term P = 0.26.

CONCLUSIONS

This retrospective cohort study found that women with preeclampsia who carry a T allele of IGF1R rs2016347 had a reduced future risk of developing HR+ breast cancer, and a reduced but not statistically significant decreased risk of non-breast cancers suggesting a possible role for the IGF-1 axis in the development of cancer in these women.