Phase II trial of alternating courses of megestrol acetate and tamoxifen in advanced endometrial carcinoma: a Gynecologic Oncology Group study

Objectives. To estimate the objective response rate and toxicity associated with alternating megestrol acetate (MA) and tamoxifen citrate (T) in women with endometrial carcinoma. Methods. Consenting patients with measurable recurrent or advanced endometrial carcinoma were eligible if they had not received prior cytotoxic or hormonal treatment. MA 80 mg BID X 3 weeks alternating with T 20 mg BID x 3 weeks orally was given. Results. Of 61 patients entered, 56 eligible patients were evaluable for toxicity and response. Fifteen patients responded (12 complete, 3 partial) for an overall response rate of 27% (90% Confidence Interval: 17-38%). In 8 of 15 (53%) responders, response duration exceeded 20 months. The response rate was 38% in patients with histologic grade 1 tumors (n = 16), 24% in those with grade 2 disease (n = 17), and 22% among patients with grade 3 disease (it = 23). Women less than or equal to 60 years (n = 16) appear to have a better response rate than those >60 years (n = 40), 44% versus 20%. The response rate in patients with extra pelvic disease (n = 42) was 31% as compared to 14% in those with strictly pelvic and/or vaginal disease (n = 14). The median progression-free survival (PFS) was 2.7 months and median overall survival was 14.0 months. Two patients experienced a grade 4 thromboembolic event. Additional toxicities included one of each grade 3 gastrointestinal, grade 3 neurologic, and grade 3 genitourinary. Conclusion. A regimen of alternating megestrol acetate and tamoxifen is active in treating endometrial cancer and may result in a prolonged complete response (CR) in some patients. (C) 2003 Elsevier Inc. All rights reserved.