P1.020. Real-World Deviations From Standard Adjuvant Immunotherapy After Esophagectomy

Abstract

Abstract Topic Esophageal Cancer: Adjuvant and Neo-Adjuvant Therapies Background Adjuvant IO is recommended within 4–16 weeks post-esophagectomy, but delays and interruptions are common in practice. Trials like CheckMate 577 permitted treatment delays of up to 10 weeks. We evaluated how often patients deviate from standard timing and explored the clinical impact of delays, interruptions, or early discontinuation. Methods We retrospectively reviewed 45 patients who underwent esophagectomy and received neoadjuvant therapy who did not have a pathologic complete response (2022 - 2025). Patients were classified into three groups based on adjuvant IO receipt and delivery: no adjuvant immunotherapy (IO) (n=14), standard IO (initiated within 10 weeks and completed without interruption; n=26), and modified IO (any delay, interruption, or early discontinuation; n=5). We compared clinical characteristics, timing intervals, and outcomes across groups. Results Baseline demographics, comorbidities, performance status and post operative outcomes were similar across all groups. The average age was 67.9 years and most patients were male (84.4%), white (64.4%), and underwent Ivor Lewis esophagectomy (93.3%) for adenocarcinoma (90.9%). Of the 31 patients who initiated IO, 83.9% completed the standard course, while 16.1% had delays, interruptions, or early discontinuation due to toxicity/complications(60%), or disease progression(40%). Time from surgery to IO was significantly longer in the modified group (81 vs 41 days, p=0.001). Treatment delays occurred in 80% of modified IO patients; 40% had interruptions or early discontinuation. Mean hospital length of stay differed significantly across groups: 17 days in the no IO group, 7 days in the standard IO group, and 6 days in the modified IO group (p=0.004). All 30-day mortality occurred in the no IO group (6.8%), compared to 0% in the other groups (p=0.06). Conclusion In this small retrospective cohort, deviations from standard adjuvant IO occurred in a minority of patients and were primarily associated with post-operative complications, toxicity, or disease progression. These deviations were not linked to system-level delays. While limited by sample size, the findings suggest that clinical recovery and disease trajectory are key factors influencing standard IO adherence. Identifying patients at risk for modification preoperatively may help tailor perioperative care and support more consistent delivery of adjuvant therapy.