PROGESTERONE-RECEPTOR CONTENT IN ENDOMETRIAL CARCINOMA CORRELATES WITH SERUM LEVELS OF FREE ESTRADIOL

Objective. To study a possible relationship between serum levels of es trogens and androgens and the tumor content of estrogen receptors and progesterone receptors in endometrial cancer. Study design. Fifty post menopausal patients were included. Receptors were determined biochemic ally in tissue cytosol by dextran charcoal-coated assay and immunohist ochemically on frozen sections. Serum sex hormones were measured by ra dioimmunoassays. Main findings. Tumor biochemical progesterone recepto r content correlated positively (p<0.05) with free estradiol serum lev els. No correlations were observed between estrogen receptor content a nd any of the serum sex hormones. The progesterone/estrogen receptor r atio, calculated from the biochemical values, correlated positively (p <0.05) with the serum levels of free estradiol. This relation was not affected by tumor histologic grade or stage. Furthermore, this ratio c orrelated positively with body mass index, probably reflecting a corre lation between body mass and serum estrogens. Biochemical and immunohi stochemical receptor values were correlated. Conclusions. These findin gs suggest that hormonal regulation of receptor levels may remain pres erved in at least some endometrial cancer cells.