Intraperitoneal mitoxantrone as consolidation treatment for patients with ovarian carcinoma in pathologic complete remission

Abstract

Background: Stages II-IV ovarian cancer in pathologic complete remission (pCR) at second-look surgery have a high relapse rate (50%) during the first 2 years. Considering relapse sites (abdomen and/or pelvis), intraperitoneal (IP) therapy is a logical approach. Mitoxantrone is an effective drug against ovarian cancer cells in vitro and is an attractive agent for IP therapy because of its very low peritoneal clearance. The value of IP mitoxantrone was studied as consolidation treatment of ovarian cancer in pCR at second-look surgery.

Methods: Fifty patients with Stages II-IV ovarian cancer (8, Stage II; 37, Stage III; 5, Stage IV) were included in this Phase II study, which began in June 1988. All patients had undergone initial cytoreductive surgery followed by 6 cyclophosphamide, doxorubicin, and cisplatin cycles. All patients were in pCR, as confirmed by second-look surgery. Consolidation treatment consists of 20 mg (total dose per cycle) IP mitoxantrone every 3 weeks for six cycles.

Results: Toxicity was limited to mild abdominal pain not requiring dose reduction (90% pain grade < or = 2). With a median follow-up of 2 years, the 5-year predicted survival is 59.8% (95% confidence interval [CI], 48.3 - 71.3), and the disease-free survival (DFS) rate is 47.3% (95% CI, 36.7 - 57.9). Patients with no or microscopic residual disease after initial surgery had a better 5-year DFS rate (75.8%) than those with macroscopic residual disease (31.2%) (P = 0.01).

Conclusion: IP mitoxantrone (20 mg/cycle) is feasible with an acceptable abdominal toxicity. The results in terms of DFS are encouraging, but a randomized study versus no treatment is necessary to prove the value of this consolidation treatment.