The etiology of
ovarian cancer appears to be associated with a long-term influence of
estrogens. However, evidence is accumulating that certain
estradiol metabolites may play a decisive role in the
carcinogenesis of
estrogen-dependent diseases. As yet little data are available on the association of
estradiol metabolites and
ovarian cancer. In vitro experiments revealed a potent stimulatory effect of certain metabolites on the proliferation of
ovarian cancer cells, which is similar to or even stronger than the effect of their parent substance 17beta-estradiol. Therefore, the pattern of endogenous
estradiol metabolism may play a role in defining
ovarian cancer risk. This may be of importance in certain predisposed women who are treated with
hormone therapy in the postmenopause. The role of
progestogens in the genesis of
ovarian cancer still remains unclear, rather a protective behaviour is suggested. Epidemiological studies indicate a possible increase in the risk for combined
estrogen/
progestin as compared to
estrogen alone. It is ambigious whether a difference exists within the various
progestogens. Apart from sex
steroids growth factors play a crucial role in the genesis of
ovarian cancer, although as yet little investigated. In vitro experiments indicate that
progestogens do not have a protective role on the growth of pre-existing
ovarian cancer cells, at least in the presence of
growth factors. Further investigations are worthwile to evaluate possible differences between the effect of the various
progestogens.