Efficacy of Platinum-based Chemotherapy for Platinum-sensitive Recurrent Ovarian Cancer During PARP Inhibitor Treatment: A Multicenter Retrospective Study
Previous studies have demonstrated low response rates and short progression-free survival (PFS) for platinum-based chemotherapy in patients with platinum-sensitive recurrent ovarian cancer during treatment with poly ADP-ribose polymerase (PARP) inhibitors. This retrospective study aimed to evaluate treatment outcomes in Japanese patients. The efficacy and safety of treatment were evaluated in 30 patients with ovarian, fallopian tube, or primary peritoneal cancers diagnosed with platinum-sensitive recurrence during PARP inhibitor treatment (administered between April 2019 and March 2025). Platinum-based chemotherapies included paclitaxel with carboplatin, paclitaxel with cisplatin, docetaxel with carboplatin, doxorubicin with carboplatin, or paclitaxel with nedaplatin. Chemotherapy was administered for six cycles, and PARP inhibitor rechallenge was performed when a treatment response was observed. The median number of platinum-based chemotherapy cycles was five (range=1-9). The objective response and disease control rates were 23.3% and 43.3%, respectively. The median PFS and overall survival were 4.5 months and 26 months, respectively. Grade 3 or higher hematological toxicities were observed, including leukopenia in 14 patients, neutropenia in 16, anemia in four, and thrombocytopenia in six. Non-hematological toxicities included nausea and constipation in one patient, hypertension in two, and carboplatin hypersensitivity in two. None of the patients discontinued chemotherapy owing to adverse events or treatment-related deaths. Subsequent platinum-based chemotherapy in patients with platinum-sensitive recurrence during PARP inhibitor treatment demonstrated a low response rate and short PFS.