There is definitely a need for the development of new drugs for the treatment and cure of
endometrial cancer. In addition there are various new drugs or phyto-remedies under development which are intended for use in the treatment and prevention of
breast cancer, for the treatment of menopausal symptoms and for
hormone replacement therapy. The efficacy of novel drugs targeting
steroid receptors in
endometrial cancers has to be evaluated and the safety of other endocrine measures on
endometrial cancers or on endometrial
carcinogenesis has to be assessed. For these experimental purposes five main classes of experimental models are available: spontaneous endometrial
tumorigenesis models in inbred animals (Donryu rats, DA/Han rats, BDII/Han rats), inoculation
tumors from chunks of
tumors (rat EnDA-
tumor, human EnCa 101
tumor) or from inoculated tumor cell lines (rat RUCA-I cells, human Ishikawa and ECC-1 cells), developmental estrogenic exposure or chemical
carcinogen exposure of CD-1 and ICR mice, transgenic approaches such as mice heterozygous regarding the tumor suppressor gene PTEN (pten(+/-)-mice) and endometrial tumor cell lines cultured under conditions promoting in vivo-like morphology and functions e.g. cell culture on reconstituted basement membrane. Although the number of models is comparatively small, most aspects related to functions of estrogenic or gestagenic substances are assessable, particularly if various experimental models are combined. Whereas models based on human endometrial
adenocarcinoma cells are widely used, the properties and advantages of animal-derived models have mainly been ignored so far.