The effect of medroxyprogesterone acetate on angiogenesis in complex endometrial hyperplasia

Objective. To evaluate the effect of orally administered medroxyprogesteron e acetate upon angiogenesis in the myometrium of patients with complex endo metrial hyperplasia. Methods. Microvessel counts in the myometrium of consecutive patients with complex endometrial hyperplasia, treated with oral medroxyprogesterone acet ate prior to hysterectomy (n = 12), were compared with microvessel counts o f consecutive control patients with complex endometrial hyperplasia without prehysterectomy medroxyprogesterone acetate treatment (n = 15). All specim ens were stained immunohistochemically for factor VIII-related antigen as a sensitive and specific marker for vascular endothelium. Areas with the hig hest angiogenic intensity, within the myometrium immediately underlying com plex endometrial hyperplasia, were selected. Three fields (x400) were selec ted for each slide, and the mean microvessel count per high-power field was calculated. Statistical analysis included factorial analysis of variance/c ovariance, and multiple regression analysis with P < 0.05 considered signif icant throughout. Results. Microvessel counts of uterine specimens of patients with complex e ndometrial hyperplasia treated with oral medroxyprogesterone acetate were s ignificantly lower than microvessel counts of control patients with complex endometrial hyperplasia without medroxyprogesterone acetate therapy (media n 20, range 11-37 versus median 38, range 20-130, respectively, P < 0.001). Conclusion. Orally administered medroxyprogesterone acetate has a significa nt antiangiogenic effect upon myometrium immediately underlying complex end ometrial hyperplasia. (C) 1999 Academic Press.