Sex Steroid Hormones and Risk of Breast Cancer

A Two-Sample Mendelian Randomization Study

Aayah Nounu; Siddhartha P. Kar; Caroline L. Relton; Rebecca C. Richmond


Breast Cancer Res. 2022;24(66) 

In This Article


Overall, our results suggest that increasing levels of testosterone, BT, estradiol and DHEAS may increase the risk of overall BC and/or ER+ (postmenopausal) BC risk, consistent with results from observational studies. For the remaining hormones, we found some suggestive associations but also acknowledge the possibility of weak instrument bias and the need for better genetic instruments. Our study provides new insights into the role of sex steroid hormones in BC risk using MR and may inform the eventual development of interventions aimed at BC prevention.