Clinical outcomes of conversion surgery after induction immunochemotherapy for borderline resectable T4 esophageal squamous cell carcinoma.

Background: The current treatment strategies for borderline resectable esophageal squamous cell carcinoma remain controversial. This study aimed to evaluate the efficacy and safety of programmed cell death 1 inhibitors combined with chemotherapy, followed by conversion surgery, for borderline resectable esophageal squamous cell carcinoma.

Methods: Patients with borderline resectable esophageal squamous cell carcinoma treated with induction immunochemotherapy from January 1, 2020 to July 1, 2023 at our hospital were retrospectively analyzed. The primary study outcome was the R0 resection rate. Secondary study outcomes included progression-free survival (PFS), overall survival (OS), pathological complete remission (pCR) rate, and safety.

Results: Forty patients with borderline resectable esophageal squamous cell carcinoma were included in the analysis. The R0 resection rate was 23/40 (57.5%); the conversion success rate was 27/40 (67.5%), and the pCR rate was 11/40 (27.5%). The median follow-up was 23.6 months (95% CI, 19.1-28.2). One-year OS and PFS rates were 77.7% and 71.8%, respectively. The incidence rate of Grade 3-4 adverse events was 10%. There was a significant difference in PFS between patients who underwent surgery and those who did not (P = 0.008, HR: 0.144 95%CI: 0.034-0.606). However, the difference in OS was not significant (P = 0.128, HR: 0.299 95%CI: 0.063-1.416). Patients who achieved clinical downstaging after induction therapy had significantly better OS (P = 0.004 h: 0.110 95%CI: 0.025-0.495) and PFS (P = 0.0016, HR: 0.106 95%CI: 0.026-0.426) compared to those who did not.

Conclusions: Conversion surgery after induction immunochemotherapy is a promising new strategy with a high conversion rate, inspiring R0 resection rate, significant pathological remission rate, and mild toxicity for borderline resectable esophageal squamous cell carcinoma.