Molecular and clinical endocrinology of the endometrium

The ovarian steroid hormones estradiol and progesterone exert their effect by interacting with their intracellular receptors, which, after ligand bind ing translocate to the nucleus and bind to the promoter regions of target g enes. The consequence is a change in the transcription rate of the target g enes,followed by a change in production of the corresponding proteins. Targ et genes of the sexual steroid hormoness include cytokines and growth facto rs, among them CSF-1,TGF-beta and LIF. The rhythm and activity of steroidog enesis, receptor modulation and transcription are reflected by cycle-specif ic proliferation and differentiation processes in the endometrium. Quantita tive and/or qualitative molecular endocrinology is of increasing interest f or better definition of morphological changes,although, as yet,the patholog ical laboratory test is of much less practical consequence than a suspiciou s vaginal sonography. In spite of the high standard of ultrasound technique s, however, most cases with slightly increased endometrial thickness show h istologically benign changes of the endometrium rather than endometrial pre cancer or cancer. This is especially true for perimenopausal women with no other clinical findings. Yet, the cancer risk is increased in women under t amoxifen therapy. Hence, as a rule,these cases,when endometrial thickness e xceeds 5 mm, need a diagnostic biopsy or abrasio.