P1.118. Delaying the Treatment Schedule in First-Line Chemotherapy Including ICIs for Esophageal Cancer Does Not Affect Survival Outcomes

Abstract

Abstract Topic Esophageal Cancer: Non-Surgical Treatment of Esophageal Cancer Background Cancer immunotherapy has dramatically changed the management of esophageal cancer. However, the impact of treatment delays on survival outcomes in first-line chemotherapy for esophageal squamous cell carcinoma (ESCC) including immune checkpoint inhibitors (ICIs) remains unclear. This study aimed to clarify the impact of treatment delays on survival outcomes in first-line chemotherapy for esophageal cancer including ICIs. Methods The study included 69 patients who underwent first-line chemotherapy using ICIs at our institution up to February 2026 and whose outcomes were known. Patients were divided into two groups: a treatment schedule delay group and a no-delay group, and a retrospective analysis of survival outcomes was performed. A treatment schedule delay was defined as a delay of 7 days or more from the scheduled start date of the second course. Results The delay group consisted of 34 patients and the no-delay group of 35. The ratios of FP (5FU + CDDP) + Pembrolizumab to FP + Nivolumab were 22:12 in the delay group and 26:9 in the non-delay group (p=0.387, chi-square test). The best response assessment was CR:PR:SD:PD ratio of 0:20:6:7 in the delay group and 0:26:5:4 in the no-delay group, with response rates of 58.8% and 74.3% (p=0.173, chi-square test) and tumor control rates of 76.5% and 88.6% (p=0.185, chi-square test), with no significant difference. The 1-year OS was 64.8% in the delay group and 60.6% in the no-delay group (p=0.851, log-rank test), and the 1-year PFS was 36.0% in the delay group and 18.1% in the no-delay group (p=0.465, log-rank test), with no significant difference observed. Conclusion In first-line chemotherapy containing ICIs for esophageal cancer, delaying the treatment schedule at the start of the second course may not affect survival outcomes. In actual clinical practice, it is appropriate to manage patients without being overly concerned about delays in the treatment schedule.