P1.075. Treatment Efficacy and Strategy in Immune Checkpoint Inhibitors Treatment for Stage IV Advanced Esophageal Cancer

Topic Esophageal Cancer: Adjuvant and Neo-Adjuvant Therapies Background The results of two trials, KeyNote590 and CheckMate648, have made it possible to use immune checkpoint inhibitors (ICIs) as first-line treatment for Stage IV esophageal cancer, and unprecedented therapeutic effects can now be expected, including multimodality therapy such as conversion surgery (CS) and chemo-radiation therapy. Treatment strategies have only just begun therefore the indications of using ICI to aim for a cure for it have not yet been established. Methods Our purpose is to examine the treatment efficacy and strategy in ICI treatment for stage IV advanced esophageal cancer. Our treatment strategy for stage IV esophageal cancer shows that three courses of ICI + 5-fluorouracil and cisplatin are administered and evaluated. When the response was recognized as CR, we performed conversion surgery or if possible ICI alone. When the response was recognized as PR, we performed conversion surgery or if possible chemo-radiotherapy. When the response was recognized as SD or PD, we performed chemo-radiotherapy or if possible ICI +Chemotherapy. The study included 51 patients diagnosed with Stage IV disease between November 2023 and January 2026 they received ICI+5FU and Cisplatin therapy, and we examined their treatment background and outcomes. Results (1)Mean age was 69 years (range 41-85) (2)Male to Female ratio 45:6 (3)PS (0:1) = 45 : 6 (4)Tumor location Upper : Middle : Lower : Junction = 5 : 3 : 18 : 17 : 8 (5)Histological type SCC : AD = 44 : 7 (6)Stage IVA:IVB = 23 : 28 (7)Treatment response assessment (response rate 53%) CR : PR : SD : PD = 3 : 24 : 17 : 7 (8)Additional treatment: CS : radiation : continued treatment : observation = 13 : 13 : 10 : 15 (9)Recurrence-free survival: cancer-bearing survival: death from current disease = 7 : 18 : 26 (10)Toxicity: bone marrow suppression: renal dysfunction : hepatic dysfunction : immune-related Adverse Events(irAE) = 14 : 6 : 5 : 21 (11) The breakdown of irAE was as follows: 6 cases of adrenal dysfunction, 10 cases of skin disorders (one patient died of sepsis from pemphigoid), 2 cases of thyroid dysfunction, 1 case of interstitial pneumonia, and 1 case of uveitis. Conclusion Multimodality treatment including surgery may serve as a novel treatment strategy for esophageal and esophagogastric junction cancer, thus provide a curative treatment option and potentially contribute to better prognosis for initially untreatable diseases. There seems to be some debate regarding the area of preventive lymph node dissection in conversion surgery and the necessity of treatment for fully cured metastatic lesions.