Objective: Uterine leiomyomas develop in women of reproductive age and regress after menopause, suggesting that they grow in a steroid hormone-dependent fashion. Furthermore, it is widely accepted that symptomatic uterine leiomyomas occur at a twofold to threefold higher frequency in black women than in white women. The present study was designed to investigate a possible physiologic role of racial differences in the myometrial estrogen receptor alpha in this phenomenon.
Methods: We compared the expression of the estrogen receptor and progesterone receptor in myometrium by ligand-binding assay and the estrogen receptor alpha by real-time polymerase chain reaction in women from different ethnic backgrounds who have uterine leiomyoma.
Results: Estrogen receptor and progesterone receptor concentrations and estrogen receptor alpha transcription levels were not statistically different between ethnic backgrounds.
Conclusion: Neither on a transcriptional nor on a protein level were there statistically relevant differences in steroid hormone receptor levels. A causative role for these receptors in the ethnic variation of leiomyoma biology seems unlikely.