Pathophysiology of deeply infiltrating
endometriosis remains controversial whereas physiopathologic mechanism of superficial
endometriosis is nearly demonstrated. Superficial peritoneal implants derive from adhesion and proliferation of endometrial cells regurgitated in peritoneum with
retrograde menstruation. Peritoneal
inflammation involving
cytokines as
TNFalpha and
aromatase over-expression might be involved in the
endometriosis invasion processus. Specific molecular defects of both eutopic and ectopic endometrium have been identified for each of the processes involved in the disease development.
Aromatase inhibitors decrease
endometriosis lesions in a mouse model of
endometriosis which was induced surgically. Few studies report efficacy of
aromatase inhibitors in human
endometriosis. Theoretically,
aromatase inhibitors should not be used alone in premenopausal women because of the resultant increase in
gonadotropin levels. Nevertheless, in premenopausal women,
aromatase inhibitors may be used in association with
Gn-RH agonists.
TNFalpha is a secretory factor of macrophages that is known to be increased in the peritoneal fluid of women with
endometriosis. Granulosa cells from these women produce higher levels of
TNFalpha. This
cytokine can stimulate adhesion and proliferation of endometrial cells and enhances metalloproteasis expression, making thus endometrial cell invasion easier. It also stimulates angiogenesis by regulating expression of
IL-8.
TNFalpha is also cytotoxic to gametes. In mice and baboon models with induced
endometriosis, anti-
TNFalpha (TNF
binding protein-1) decreases AFS score stage and reduces in size the endometriotic foci. No clinical assay has studied
TNFalpha efficacy on human
endometriosis.