Progesterone From Ovulatory Menstrual Cycles Is an Important Cause of Breast Cancer

Authors

Herjan J T Coelingh Bennink
Iman J Schultz
Marcus Schmidt
V Craig Jordan
Paula Briggs
Jan F M Egberts
Kristina Gemzell-Danielsson
Ludwig Kiesel
Kirsten Kluivers
Jan Krijgh
Tommaso Simoncini
Frank Z Stanczyk
Robert D Langer

Publication Date

5-30-2023

Journal

Breast Cancer Research

Abstract

Many factors, including reproductive hormones, have been linked to a woman's risk of developing breast cancer (BC). We reviewed the literature regarding the relationship between ovulatory menstrual cycles (MCs) and BC risk. Physiological variations in the frequency of MCs and interference with MCs through genetic variations, pathological conditions and or pharmaceutical interventions revealed a strong link between BC risk and the lifetime number of MCs. A substantial reduction in BC risk is observed in situations without MCs. In genetic or transgender situations with normal female breasts and estrogens, but no progesterone (P4), the incidence of BC is very low, suggesting an essential role of P4. During the MC, P4 has a strong proliferative effect on normal breast epithelium, whereas estradiol (E2) has only a minimal effect. The origin of BC has been strongly linked to proliferation associated DNA replication errors, and the repeated stimulation of the breast epithelium by P4 with each MC is likely to impact the epithelial mutational burden. Long-lived cells, such as stem cells, present in the breast epithelium, can carry mutations forward for an extended period of time, and studies show that breast tumors tend to take decades to develop before detection. We therefore postulate that P4 is an important factor in a woman's lifetime risk of developing BC, and that breast tumors arising during hormonal contraception or after menopause, with or without menopausal hormone therapy, are the consequence of the outgrowth of pre-existing neoplastic lesions, eventually stimulated by estrogens and some progestins.

Keywords

Female, Humans, Progesterone, Breast Neoplasms, Menstrual Cycle, Estrogens, Estradiol, Pharmaceutical Preparations, Breast cancer, Menstrual cycles, Progesterone, Estrogens, Tumor doubling time, DNA replication, WNT4

Comments

PMID: 37254150