Long-term follow-up of the first randomized study of cisplatin versus carboplatin for advanced epithelial ovarian cancer

A phase III trial was performed between October 1981 and June 1984 to compare the efficacy of single-agent cisplatin and single-agent carboplatin in previously untreated patients with International Federation of Gynecology and Obstetrics stage III or IV carcinoma of the ovary following surgery. This report describes the survival rates of patients in this study after a minimum follow-up duration of 8 years.

Sixty-four patients were randomized to receive cisplatin and 67 patients to receive carboplatin. Cisplatin was administered every 4 weeks for a total of 10 courses, courses 1 to 5 at a dosage of 100 mg/m2 and courses 6 to 10 at 30 mg/m2. Carboplatin was administered at a dosage of 400 mg/m2 every 4 weeks for 10 courses. Patients who had clinical or radiologic evidence of response after five courses of chemotherapy underwent second-look surgery. The study was designed to allow crossover between the two arms. Thirteen patients were excluded from response analyses because they were incorrectly randomized. Patients were crossed over to the other arm of the study because of progressive disease (PD), nonresponse, or toxicity.

The overall response rate for patients randomized to the cisplatin arm was 53.8% (28 of 52; 95% confidence interval [CI], 39% to 68%) and for those randomized to the carboplatin arm, 38.4% (20 of 52; 95% CI, 25% to 53%). There were 16 (30.8%) and 14 (26.9%) complete remissions (CRs) in the cisplatin and carboplatin arms, respectively. None of these differences were statistically significant. The median duration of response for the cisplatin and carboplatin arms was 21 months and 17 months, and the 5-year relapse-free survival rates were 22% and 25%, respectively. The median survival durations for the cisplatin and carboplatin arms were 19.5 and 13 months, and the 5-year survival rates were 15% (95% CI, 8% to 26%) and 19% (95% CI, 11% to 30%), respectively. None of these differences was statistically significant. The median follow-up duration of patients is 9 years. Crossover due to toxicity was more frequent in the cisplatin than the carboplatin arm, occurring in 50% and 3.3% of patients, respectively.

The mature data from this study of patients with advanced ovarian cancer show that cisplatin and carboplatin have similar long-term survival results.