Impact of the interval between neoadjuvant immunotherapy and surgery on prognosis in esophageal squamous cell carcinoma (ESCC): a real-world study.

Background: The time interval between neoadjuvant immunotherapy and surgery is 6 weeks for esophageal squamous cell carcinoma (ESCC), but whether delayed surgery affects prognosis remains unclear.

Methods: Clinical data of locally advanced ESCC who underwent neoadjuvant immunotherapy followed by esophagectomy from November 2019 to December 2022 were collected. The surgery outcomes and prognosis were compared between short-interval (time to surgery ≤ 6 weeks) and long-interval groups (time to surgery > 6 weeks).

Results: 152 patients were enrolled totally, with a ratio of 91:61 between short-interval and long-interval groups. The rate of pathological complete response in the short-interval and long-interval groups were 34.1% and 24.6% (P = 0.257). Delayed surgery did not have a significantly impact on the number of lymph node dissections (P = 0.133), operative duration (P = 0.689), blood loss (P = 0.837), hospitalization duration (P = 0.293), chest drainage duration (P = 0.886) and postoperative complications (P > 0.050). The 3-year Overall survival (OS) rates were 85.10% in the short-interval group, and 82.07% in the long-interval group (P = 0.435). The 3-year disease-free survival (DFS) rates were 83.41% and 70.86% in the two groups (P = 0.037). Subgroup analysis revealed that patients with a favorable response to immunotherapy (tumor regression grade 0) exhibited inferior 3-year OS (long-interval vs. short-interval: 51.85% vs. 91.08%, P = 0.035) and DFS (long-interval vs. short-interval: 47.40% vs. 91.08%, P = 0.014) in the long-interval group.

Conclusions: Delayed surgery after neoadjuvant immunotherapy does not further improve pathological response; instead, it resulted in a poorer DFS. Especially for patients with a favorable response to immunotherapy, delayed surgery increases the risk of mortality and recurrence.