Efficacy and safety of high-dose cisplatin and cyclophosphamide with glutathione protection in the treatment of bulky advanced epithelial ovarian cancer.

Recent efforts to improve the response rates in advanced ovarian cancer with the use of high-dose cisplatin have been limited by unacceptable toxicity. Based on experimental and clinical studies indicating that reduced glutathione (GSH) is a protective agent against cisplatin-induced toxicity, a new high-dose regimen including GSH as a chemoprotector was designed in an attempt to improve the efficacy and therapeutic index of cisplatin. A total of 40 consecutive patients with stage III (bulky) and IV ovarian carcinoma were treated with cisplatin (40 mg/m2 daily for 4 consecutive days) and cyclophosphamide (600 mg/m2 i.v. on day 4). The treatment was repeated every 3-4 weeks for five courses unless progression or severe toxicity occurred. Before each cisplatin administration, patients received GSH (1,500 mg/m2) i.v. over 15 min, with a standard i.v. hydration (2,000 ml fluid) without diuretics. Debulking surgery was initially attempted in 18 patients and, after 2-3 courses, in 16 patients; it could not be carried out in 6 patients. Three patients were not evaluable for response because they prematurely discontinued their treatment. In all, 23 patients (62%) achieved complete clinical remission (negative second-look laparotomy in 16), with an overall (complete + partial) response rate of 86%; 2 patients achieved disease-free status following second surgery. Nausea/vomiting was the most severe acute toxic effect; myelosuppression was acceptable. Renal impairment was effectively prevented by GSH. Neurotoxicity that was not associated with motor dysfunction was the most significant cumulative toxicity in patients (24/32) receiving 4-5 courses. The results of this study indicate that the use of GSH is a safe new method for high-dose cisplatin administration. This regimen is well-tolerated and very effective in ovarian cancer patients with bulky disease and warrants further evaluation.