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Unopposed Estrogen

Meaning

Unopposed estrogen is a clinical term describing the therapeutic or endogenous state where estrogen stimulates the endometrium, the lining of the uterus, without the counterbalancing, protective effects of progesterone or a progestin. This lack of opposition permits continuous, unchecked endometrial proliferation, significantly increasing the risk of developing endometrial hyperplasia and, subsequently, endometrial carcinoma. Careful clinical management is necessary to mitigate this oncogenic risk in patients receiving estrogen replacement therapy.