Immunohistochemical study of intracellular estradiol in human gastric cancer

Tissues from primary human gastric cancers were examined for intracellular estradiol (E2) by using the avidin-biotin-peroxidase complex (ABC) immunohistochemical method on formalin-fixed paraffin-embedded sections. Reaction products of E2 were located only in the cytoplasm of the cancer cells, and not detected in noncancerous gastric epithelium. E2-positive tissues were found in 23 (44.2%) of 52 male patients, seven (20.6%) of 34 female patients and a total of 30 (34.9%) of 86 patients. In male patients, E2-positive cases occurred without age distinction. In female patients, however, E2 was not found in patients in older age groups, especially patients in the postmenopausal state. Microscopically, E2 was found frequently in intestinal type of cancers in male patients and in cancer with scirrhous growth pattern, in female patients. This is the first report of the demonstration of E2 in gastric cancer. The findings suggest that hormonal factors are involved in gastric cancer, and that the cancers contain endocrinic characteristics.