The efficacy and safety of adjuvant immunotherapy after neoadjuvant immunotherapy combined with chemotherapy in locally advanced resectable esophageal squamous cell carcinoma: A real-world study.

e16146 Background: The promising therapeutic outcomes of neoadjuvant immunotherapy with chemotherapy (NAIC) in the treatment of resectable locally advanced esophageal squamous cell carcinoma (LA-ESCC) have been confirmed by several clinical trials. However, the potential benefits of adjuvant therapy for LA-ESCC patients remain unclear. Methods: We analyzed the LA-ESCC patients underwent NAIC and adjuvant immunotherapy between January 2020 and September 2023. The effectiveness and feasibility of adjuvant immunotherapy were evaluated. Results: A total of 112 ESCC patients were included. With a median follow-up of 24.0 months, all 112 patients had an R0 resection, and 23 patients (20.5%) achieved pathological complete response (pCR). The median DFS and OS were 18.5 and 24.0 months. The 12- and 24-month DFS rates were 91.0% and 81.7%, and the 12- and 24-month OS rates were 99.1% and 96.8%, respectively. Patients with BMI ≥20 kg/m2 had a longer 24-month DFS rate compared with those with BMI < 20 kg/m2 (87.1% vs 62.0%, P = 0.034). Additionally, patients with postoperative pCR than those with non-pCR achieved better 12-month (100% vs 88.6%) and 24-month (100% vs 77.3%, P < 0.001) DFS. Superior DFS rates were acquired in patients with ypT0-1 (12-month: 98.1% vs 84.6%, P = 0.008, 24-month: 95.4% vs 70.7%, P < 0.001), ypN0 (12-month: 96.9% vs 83.1%, P = 0.019, 24-month: 88.9% vs 72.2%, P = 0.042), obtained T (12-month: 96.2% vs 78.3%, P = 0.018, 24-month: 92.8% vs 56.0%, P < 0.001) or TNM (12-month: 96.5% vs 84.8%, P = 0.033, 24-month: 90.5% vs 72.5%, P = 0.02) downstaging. A total of 79 (72.5%) patients experienced treatment-related adverse events (TRAEs), and the most common TRAEs were digestive reactions (52.3%) and myelosuppression (38.5%). The incidence of grade ≥3 adverse events occurred in 8 (7.3%) patients. Conclusions: The combination of NAIC and adjuvant immunotherapy displays short survival benefits and has an acceptable safety profile, which may be an effective treatment strategy for LA-ESCC patients.