Serum CA-125 as a marker of disease activity in uterine papillary serous carcinoma.

Papillary serous carcinoma of the endometrium exhibits many clinical features of ovarian cancer, including a high metastatic potential and response to platinum-based chemotherapy. We investigated the clinical utility of the serum CA-125 antigen level, an established marker of response or progression in ovarian cancer, to serve as a indicator of these events in patients with this highly malignant subtype of endometrial cancer. Of 21 individuals with this cancer treated in our program from 11/91 to 6/97, 16 had baseline CA-125 determinations prior to the administration of chemotherapy, of whom 13 were elevated above the normal range. Of these 13 patients, 8 (57%) experienced either a major reduction or normalization of CA-125 levels following therapy, consistent with their clinical course at that point in time. Similarly, of 11 patients who ultimately relapsed, 8 (73%) were found to have a rise in the CA-125 antigen level which closely corresponded to, or proceeded, clinical relapse. A single patient was demonstrated to have disease progression with a declining level of CA-125. We conclude the serum CA-125 antigen level is a useful indicator of disease response or progression in individuals with papillary serous carcinoma of the endometrium.