Randomized phase II trial of paclitaxel plus carboplatin therapy versus irinotecan plus cisplatin therapy as first-line chemotherapy for clear cell adenocarcinoma of the ovary: a JGOG study

Introduction: Paclitaxel plus carboplatin (TC) is generally considered to be the "gold standard" regimen for treatment of epithelial ovarian carcinomas. Little data are available, however, on the use of this regimen in patients with clear cell adenocarcinoma of the ovary (CCC). Combination chemotherapy with irinotecan hydrochloride plus cisplatin has been reported to be effective for primary and recurrent or resistant CCC. We compared these 2 combinations in patients with CCC. Methods: Patients (n = 99) with CCC were randomly assigned to receive either 180 mg/m2 paclitaxel on day 1 plus AUC 6 mg/mL × minute carboplatin on day 1 every 21 days (TC arm) or 60 mg/m2 irinotecan hydrochloride on days 1, 8, 15 plus 60 mg/m2 cisplatin on day 1 every 28 days (CPT-P arm). Results: Percentages of patients receiving the scheduled 6 cycles of chemotherapy in the TC and CPT-P arms were 70.8% and 72.0%, respectively. Although toxicity was well tolerated in both arms, the toxicity profile of each arm differed. Progression-free survival (PFS) showed no significant difference between the 2 treatment groups. Because there were more patients with large residual disease in the CPT-P arm, we performed a subset analysis by removing those patients, and then compared the PFS with that of patients without residual disease or with residual disease less than 2 cm. The PFS tended to be longer in the CPT-P group, although the difference was not statistically significant. Conclusions: A phase III randomized trial is required to elucidate the effectiveness of CPT-P combination chemotherapy for CCC.