Second-Line Chemotherapy in Recurrent Clear Cell Ovarian Cancer: Results from the Multicenter Italian Trials in Ovarian Cancer (MITO-9).

Background and Aims: Ovarian clear cell carcinoma (CCC) has a poorer prognosis than other subtypes of ovarian cancer. In this study, we evaluated the responsiveness to second-line chemotherapy in recurrent ovarian CCC. Methods: The MITO-9 project investigated a cohort of patients observed between 1991 and 2007 in 20 centers. We identified 72 out of 240 patients with recurrent disease (28% stage I-II and 72% stage III-IV at diagnosis). Results: In 56% of patients, the clear cell histology was pure. Twenty-five patients were platinum-resistant, 18 were platinum-sensitive with a platinum-free interval (PFI) of 6-12 months, and 29 had a PFI >12 months. Upon recurrence, 47% of patients were treated with platinum chemotherapy according to the PFI. The overall response rate (RR) to platinum was 80%, with 55, 100, and 80% RR in patients with PFI of 6-12, >12, and >24 months. The RR to nonplatinunn agents in resistant patients was 33%. Among the nonplatinum agents used in primary and secondary resistant cases, gemcitabine, administered in 12 cases, had a higher activity (RR = 66%) compared to topotecan or liposomal doxorubicin (n = 31; RR = 33 and 10%, respectively). Conclusions: This study showed that the treatment of recurrent ovarian CCC should be based on the PH as in the other subtypes. Data in platinum-resistant patients suggest gemcitabine as the drug with the highest activity. We recommend that gemcitabine be studied prospectively in a phase 2 trial. (C) 2014 S. Karger AG, Basel