CA 125 may not reflect disease status in patients with uterine serous carcinoma

BACKGROUND. Although CA 125 level correlates with response to therapy in patients with serous carcinoma of the ovary, the utility of CA 125 in patients with high risk or metastatic endometrial carcinoma has not been established. METHODS. CA 125 was tested as a marker of disease status in patients with endometrial serous carcinoma (SC) undergoing adjuvant chemotherapy. All patients received monthly intravenous chemotherapy with cisplatin, cyclophosphamide, and doxorubicin at standard doses (median number of courses, 6; range, 2-8 courses). Serum CA 125 was measured at diagnosis and before each course. After the completion of chemotherapy, patients were examined every 3 months and the CA 125 level was measured. RESULTS. A total of 220 serum specimens from 15 patients with invasive SC were analyzed. All five patients who died of disease had clinical or radiographic evidence of tumor, which CA 125 elevation did not precede or predict. One patient with advanced disease at staging never had an elevated CA 125 level but died of disseminated disease 14 months after diagnosis. At last follow-up, 3 patients who were without evidence of disease > 36 months from diagnosis had significant false-positive elevations in their CA 125 level (>50 u/mL) lasting 1, 2, and 4 months, respectively, during therapy. The sensitivity for advanced disease was only 57% at presentation. CONCLUSIONS. CA 125 may reflect advanced stage disease and pretend a poor prognosis, but may not add information to that gained by history and physical examination, preoperative studies, or surgery that already is mandated by this high risk histology. This circulating marker appears to have limited utility in monitoring the effects of adjuvant therapy for SC, and may not predict recurrence in the absence of other clinical findings.