Tissue expression of Sialyl Tn antigen in gynecologic tumors.

OBJECTIVES

To investigate tissue expression of Sialyl Tn antigen (STN) in gynecologic tumors, and to compare with its appearance in blood circulation.

METHODS

Surgical specimens were obtained from 24 patients with malignant gynecologic diseases, including 7 ovarian cancers, 13 cervical cancers, 3 endometrial cancers, and 1 vulval cancer. Control tissues were also obtained at surgery from 28 patients with benign tumors of the ovary or uterus.

RESULTS

Anti-STN monoclonal antibody (TKH-2) positively identified 6 (86%) of 7 ovarian cancers, 11 (85%) of 13 cervical squamous-cell carcinomas, but none of 3 endometrial cancers. None of the 28 benign tissues, including 11 ovarian benign tumors, showed positive immunostaining for STN, except 1 with an ovarian chocolate cyst which showed weak staining for STN. No expression was found in normal squamous epithelium distant from the lesion. Serum STN antigen was positive in 4 of 7 ovarian cancers (cutoff = 39 U/ml), but only in 2 of 13 cervical cancers, and none in the 3 endometrial cancers.

CONCLUSIONS

These findings indicate different behaviors in the appearance of STN in tumor tissue and blood circulation, and also suggest the possible applicability of STN to immunohistochemical diagnosis of squamous-cell carcinomas.