Extending the platinum-free interval: The impact of omitting 2nd line platinum chemotherapy in intermediate platinum-sensitive ovarian cancer

AbstractObjectivesPatients with epithelial ovarian cancer (EOC) recurring between 6 and 12 months after primary platinum chemotherapy have worse prognosis than those recurring in >12 months. Artificially prolonging the platinum-free interval (PFI) with cytotoxic chemotherapy was tested in MITO-8 with poor outcomes. This study aimed to determine the impact of using non-platinum or targeted therapy in 2nd line treatment of EOC patients recurring 6–12 months after completion of primary platinum-based chemotherapy. MethodsA multi-institutional retrospective review of 177 patients with recurrent EOC and PFI of 6–12 months following primary chemotherapy was performed comparing platinum versus non-platinum chemotherapy or targeted therapy for 2nd line treatment. PFI1 was defined as the date of last chemotherapy to date of recurrence. PFS2/3 were defined as start of 2nd or 3rd line chemotherapy to start of subsequent line. ResultsOf 177 patients, the majority of patients were Caucasian, had serous histology, and underwent primary cytoreductive surgery. Median PFI1 was 8.2 months (95% CI 8–9 months). Second line platinum was omitted in 28% of patients. Bevacizumab was used in 2nd line in 16% of patients; 19% received other targeted therapies. Median PFS2 for platinum chemotherapy was longer than non-platinum (7.1 vs 3 months, p = 0.0114). Median PFS2 was significantly longer for platinum vs. targeted therapy (7.1 vs. 3 months p = 0.0431). Median OS for platinum in 2nd line vs. no platinum was 43.6 vs. 37.6 months ( p = 0.0174). ConclusionsUse of non-platinum chemotherapy and even targeted therapy to prolong PFI in patients with EOC recurring between 6 and 12 months leads to worse survival.