This randomized, open label, phase III clinical trial (1988-1992) compared the efficacy and safety of a dose-dense regimen of single-agent cisplatin with a standard 3-weekly schedule in first-line chemotherapy for advanced epithelial ovarian cancer. Two hundred eighty-five patients were randomly assigned to the experimental dose-dense arm (cisplatin 50 mg/m(2) weekly × nine cycles) or to the control (standard treatment) arm (cisplatin 75 mg/m(2), administered on day 1 every 21 days × six cycles). The primary outcome was progression-free survival (PFS). Secondary outcomes were overall survival (OS), overall response to chemotherapy, and toxicity. Toxicity and response to treatment were compared with the χ(2) test using trend or exact correction. PFS and OS were estimated by Kaplan-Meier analyses and treatment hazard ratios (HRs) with the Cox proportional hazards model. All statistical tests were two-sided. After a median follow-up of 16.8 years, no differences were observed between the two treatments in PFS (experimental arm: 17.2 months; control arm: 18.1 months; HR = 1.08, 95% confidence interval [CI] = 0.83 to 1.40; P = .57) and in OS (experimental arm: 35 months; control arm: 32 months; HR = 0.97, 95% CI = 0.75 to 1.26; P = .97). Thus, increasing dose intensity of cisplatin does not improve PFS or OS compared with standard chemotherapy.