SEQUENTIAL ESTROGEN AND PROGESTOGEN THERAPY - ASSESSMENT OF PROGESTATIONAL EFFECTS ON THE POSTMENOPAUSAL ENDOMETRIUM

Healthy postmenopausal women were randomly assigned to groups receivin g 28-day treatment cycles of estradiol (E2) valerate (2 mg, days 12-21 ) combined with medroxyprogesterone acetate (10 mg, days 12-21) (N = 1 8), 17-beta-estradiol (1.5 mg, days 1-24) combined with desogestrel (1 50-mu-g, days 13-24) (N = 20), or placebo (N = 18). The progestational effects on the endometrium were assessed by histology, uterine bleedi ng pattern, and biochemical markers of secretion measured in endometri al tissue (E2 and isocitrate dehydrogenase) and serum (placental prote in 14). After 2 years of therapy, 24 women in the hormone groups had s ecretory endometrium and 13 had atrophic endometrium; in the placebo g roup, the results were one and 15, respectively. Withdrawal bleeding g enerally started between days 9-12 after the addition of progestogen i n the E2-medroxyprogesterone acetate group, and between days 14-17 in the E2-desogestrel group. All three biochemical markers of secretion w ere increased in each of the hormone-treated groups compared with the placebo group (P < .01-.001). Serum placental protein 14 was twice as high in the secretory as in the atrophic phase (P < .01). Isocitrate d ehydrogenase, but not E2 dehydrogenase, was also higher in the secreto ry phase (P < .05). Only serum placental protein 14 was significantly related to the uterine bleeding pattern (P < .01). We conclude that se rum placental protein 14 reflects both endometrial histology and bleed ing pattern and may be a useful marker of progestational effects on th e endometrium. The markers of secretion measured in endometrial tissue are not as reliable for endometrial histology or bleeding pattern.