Background/rationale: Time between completion of last platinum-based chemotherapy (PBC) and recurrence is predictive of outcomes in recurrent ovarian cancer; however, its applicability to endometrial cancer (EC) remains uncertain. This retrospective real-world study assessed platinum-free interval (PFI: the duration between completion of first-line PBC and the start date of any second-line therapy) for EC (funding: GSK; study number: 218296).
Methods: Patients from the US Flatiron Health electronic health record-derived deidentified database with advanced/recurrent EC who received first-line PBC between 01/01/2013 and 31/08/2022 were included. Overall survival (OS), time to treatment discontinuation (TTD), time to next treatment (TTNT) were analyzed using Kaplan-Meier methods; the association between PFI and clinical outcomes was examined using Cox regression models.
Impact on practice: Of 843 patients, 575 (68%), 147 (17%), and 121 (14%) had a PFI of <6, 6-12, and ≥12 months, respectively. Advanced disease, carcinosarcoma histology, or history of surgery/radiation were associated with a shorter PFI, and body mass index of ≥40 kg/m2 or PD-L1 negative/not detected with a longer PFI (All P<.05). For patients with a PFI of <6, 6-12, or ≥12 months, median OS was 12.7, 17.9, 30.5 months, median TTD was 3.6, 4.4, 5.1 months, median TTNT was 9.8, 8.3, 12.6 months, respectively. Compared with patients with a ≥12-month PFI, those with a shorter PFI had a significantly higher risk of death, when adjusted for confounders (<6 month PFI: HR, 1.71 [95% CI, 1.27-2.29]; 6-12 month PFI: HR, 1.57 [95% CI, 1.12-2.20]).
Conclusions: Our data suggest that platinum sensitivity is an applicable concept in advanced/recurrent EC and is associated with OS and may have implications for treatment selection and informing clinical trial design.
© 2025 American Society of Clinical Oncology, Inc. Reused with permission. This abstract was accepted and presented at the 2025 ASCO Annual Meeting. All rights reserved.