Estrogen's effects in chronic autoimmune/inflammatory diseases and progression to cancer.

Endocrine-immune system interactions are the basis for predominance of autoimmune diseases in women with differences between the fertile and the postmenopausal periods. B cell-driven diseases reach the maximum incidence rate in the reproductive years, at least in women under the effects of serum estrogens and their metabolites (endocrine synthesis). On the other hand, the prevalent peripheral synthesis of estrogens, especially in advanced ages (intracrine synthesis), through the action of aromatases, modulate the immune/inflammatory response in peripheral tissues similarly in both female and male patients (final common pathway). Interestingly, tissue injury that occurs during chronic immune/inflammatory reaction induces tissue repair and homeostatic responses including cell proliferation, growth factor production and angiogenesis that might facilitate cancer progression. The successful treatment of chronic immune/inflammatory diseases obtained by using medications initially developed for use in oncology, such as antiproliferative drugs, B-cell depleting monoclonal antibodies support the inflammation-cancer link.