Safety and efficacy of neoadjuvant treatment with immune checkpoint inhibitors in esophageal cancer: real-world multicenter retrospective study in China.

Immune checkpoint inhibitors (ICIs) have shown a powerful benefit in the neoadjuvant therapy for esophageal cancer, but evidence for its safety and efficacy is limited and may not reflect real-world practice. We retrospectively reviewed the database of treatment-naive patients from 15 esophageal cancer centers in China who received ICIs as neoadjuvant treatment for locally advanced esophageal cancer from May 2019 to December 2020. The primary endpoints were rate and severity of treatment-related adverse events (TRAEs) and immune-related adverse events (irAEs). Secondary endpoints included pathologically complete response (pCR) rate, R0 resection rate, mortality and morbidity. Among the 370 patients, 311 (84.1%) were male with a median age of 63 (range: 30-81) years and stage III or IVa disease accounted for 84.1% of these patients. A total of 299 (80.8%) patients were treated with ICIs and chemotherapy. TRAEs were observed in 199 (53.8%) patients with low severity (grade 1-2, 39.2%; grade 3-4, 13.2%; grade 5, 1.4%), and irAEs occurred in 24.3% of patients and were mostly of grade 1-2 severity (21.1%). A total of 341 (92.2%) patients had received surgery and R0 resection was achieved in 333 (97.7%) patients. The local pCR rate in primary tumor was 34.6%, including 25.8% of ypT0N0 and 8.8% of ypT0N+. The rate of postoperative complications was 41.4% and grade 3 or higher complications occurred in 35 (10.3%) patients. No death was observed within 30 days after surgery, and three patients (0.9%) died within 90 days postoperatively. This study shows acceptable toxicity of neoadjuvant immunotherapy for locally advanced esophageal cancer in real-world data. Long-term survival results are pending for further investigations.