Randomized phase III trial of irinotecan plus cisplatin compared with paclitaxel plus carboplatin as first-line chemotherapy for ovarian clear cell carcinoma: JGOG3017/GCIG trial

Purpose: Clear cell carcinoma (CCC) is a rare histologic subtype that demonstrates poor outcomes in epithelial ovarian cancer. The Japanese Gynecologic Oncology Group conducted the first randomized phase III, CCC-specific clinical trial that compared irinotecan and cisplatin (CPT-P) with paclitaxel plus carboplatin (TC) in patients with CCC. Patients and Methods: Six hundred sixty-seven patients with stage I to IV CCC of the ovary were randomly assigned to receive irinotecan 60 mg/m² on days 1, 8, and 15 plus cisplatin 60 mg/m² on day 1 (CPT-P group) every 4 weeks for six cycles or paclitaxel 175 mg/m² plus carboplatin area under the curve 6.0mg/mL/min on day 1 every 3 weeks for six cycles (TC group). The primary end point was progressionfree survival. Secondary end points were overall survival, overall response rate, and adverse events. Results: Six hundred nineteen patients were clinically and pathologically eligible for evaluation. With a median follow-up of 44.3 months, 2-year progression-free survival rates were 73.0% in the CPT-P group and 77.6% in TC group (hazard ratio, 1.17; 95% CI, 0.87 to 1.58; P =.85). Two-year overall survival rates were 85.5% with CPT-P and 87.4% with TC (hazard ratio, 1.13; 95% CI, 0.80 to 1.61; one-sided P =.76). Grade 3/4 anorexia, diarrhea, nausea, vomiting, and febrile neutropenia occurred more frequently with CPT-P, whereas grade 3/4 leukopenia, neutropenia, thrombocytopenia, peripheral sensory neuropathy, and joint pain occurred more frequently with TC. Conclusion: No significant survival benefit was found for CPT-P. Both regimens were well tolerated, but the toxicity profiles differed significantly. Treatment with existing anticancer agents has limitations to improving the prognosis of CCC.