An immunohistochemical study of endogenous estradiol and testosterone in human colo-rectal cancer tissues

An immunohistochemical method (peroxidase antiperoxidase method) was carried out to examine the distribution of endogenous estradiol (E2) and testosterone (Te). One hundred and twenty four (48.2%) of 257 colo-rectal cancer cases, and 36.7% of male cases and 58.4% of female cases revealed E2-immunostain. This immunohistochemical reaction for E2 was found more frequently in female patients than in male patients, while Te-immunostain was found in 15 (17.6%) of 85 colo-rectal cancer cases. E2 and Te were demonstrated mainly in the cytoplasms and occasionally in the nuclei of cancer cells. Since E2 or Te-positive cancer cells were mainly distributed in the deeper or invasive portion of tissue sections, it might deserve further investigation to elucidate a certain relationship between cancer growth and endogenous sex-hormones.