Abstract
Objective To study the effect of E2 and P on the epithelial cell cycle of normal human breast in vivo.
Design Double-blind, randomized study. Topical application to the breast of a gel containing either a placebo, E2, P, or a combination of E2 and P, daily, during the 10 to 13 days preceding breast surgery.
Patients Forty premenopausal women undergoing breast surgery for the removal of a lump. MAIN OUTCOME MEASURES. Plasma and breast tissue concentrations of E2 and P. Epithelial cell cycle evaluated in normal breast tissue areas by counting mitoses and proliferating cell nuclear antigen immunostaining quantitative analyses.
Results Increased E2 concentration increases the number of cycling epithelial cells. Increased P concentration significantly decreases the number of cycling epithelial cells.
Conclusion Exposure to P for 10 to 13 days reduces E2-induced proliferation of normal breast epithelial cells in vivo.
topical progesterone breast tissue effects, estradiol breast cell proliferation, progesterone breast cancer protection, transdermal hormone breast epithelium, bioidentical progesterone antiproliferative, estrogen induced breast proliferation, percutaneous progesterone gel, progesterone reduces estrogen proliferation, breast epithelial cell cycle hormones, natural progesterone breast health, mitotic index progesterone estradiol, hormone replacement breast safety
Keywords
Administration, Topical, Adolescent, Adult, Blood/metabolism, Breast/cytology/drug Effects/metabolism, Cell Cycle/drug Effects, Cell Division, Double-Blind Method, Estradiol/administration & Dosage/pharmacokinetics/pharmacology, Female, Gels, Humans, Middle Aged, Mitotic Index, Progesterone/administration & Dosage/pharmacokinetics/pharmacology, Proliferating Cell Nuclear Antigen/metabolism, Gels, Proliferating Cell Nuclear Antigen, Progesterone, Estradiol,