CA 125 in serum and tumor from patients with uterine sarcoma.

Serial serum samples of 33 patients with primary sarcoma of the uterus were analyzed for CA 125 and frozen tissue sections of tumor from 23 patients were tested for this antigen. Before treatment, 12 of 30 evaluable patients showed serum CA 125 levels> 16 Uml-1 (40%). There was no relationship between serum CA 125 level and the histologic subtype. Patients with serum CA 125> 16 Uml-1 showed extrauterine tumor sites in 67% of the cases versus 33% in patients with normal CA 125 determinations (P = 0.026). In (FIGO) stages I and II, elevated serum CA 125 levels prior to surgery were associated with a poor prognosis (P = 0.043). Patients with recurrent or progressive disease demonstrated serum CA 125 levels> 16 Uml-1 in 14 of the 20 cases (70%). Sarcoma cells were completely negative for CA 125, whereas positivity was observed in the epithelial component of mixed Müllerian tumors. The source of the elevated serum CA 125 levels in patients with uterine sarcoma may be stimulated mesothelial cells.