Background: To evaluate the efficacy and safety of long-term conservative therapy with medroxyprogesterone acetate (MPA) for endometrial carcinoma in young patients who had experienced failure after initial therapy or relapse, we reviewed the clinical and pathologic records of eight patients diagnosed with well-differentiated endometrial adenocarcinoma without myometrial invasion who were treated with MPA for over 6 months because of treatment failure or relapse.
Results: The average duration of MPA treatment was 22 months. All patients were followed-up for a mean of 76.5 months. Seven patients responded to initial MPA treatment within a period of 14 months (mean, 7.9 months). All these patients experienced relapse and the mean time to relapse was 11.6 months (range, 4-33 months). All six patients with relapse were treated with additional treatments of MPA, and all but one responded to this treatment within a period of 16 months (mean, 8.0 months). Six patients ultimately underwent hysterectomy. All presented well-differentiated endometrioid adenocarcinomas without extrauterine disease. Three became pregnant and two delivered full-term normal infants. No patient died of the disease.
Conclusion: Although lesions are expected to disappear with prolonged MPA treatment, this form of progestin therapy is hazardous because recurrence occurs frequently. Only strictly selected patients should therefore be indicated for long-term MPA treatment and careful evaluation before and after treatment should be performed.