Serum levels of steroid sulfatase protein in gynecologic carcinomas

Steroid sulfatase (STS) desulfates a number of 3 beta-hydroxysteroid sulfates, converting inactive steroid hormone to the active form. We have established an enzyme-linked immunosorbent assay (ELISA) of STS by using polyclonal antibody against STS purified from human placenta to measure the amount of the enzyme protein in sera. ELISA was performed by a 'Sandwich' method using a peroxidase conjugated anti-STS IgG Fab' fragment. A range of STS of 10-1,500 ng/ml in serum was assayed by this method. When the serum STS from the patients with gynecologic carcinomas was assayed by the ELISA, the level was significantly elevated in endometrial carcinoma (P < 0.05) and ovarian carcinoma (P < 0.01), respectively, as compared with that of normal healthy women.