Comparison of neoadjuvant chemoimmunotherapy with or without concurrent radiotherapy for locally advanced resectable esophageal squamous cell carcinoma: a multicenter retrospective study.

The aim of this study was to evaluate the safety and clinical benefits of adding concurrent radiotherapy to neoadjuvant chemoimmunotherapy in patients with resectable locally advanced esophageal squamous cell carcinoma (ESCC). This multicenter retrospective study enrolled eligible ESCC patients treated between November 2019 and July 2020 from four hospitals. Baseline characteristics were collected, and patients were categorized into two groups based on neoadjuvant regimens: the chemoimmunotherapy group (CI group) and the chemoimmunotherapy with concurrent radiotherapy group (CIR group). Treatment-related complications, surgical outcomes, pathological response, tumor recurrence, and survival were analyzed. A total of 78 eligible patients were included: 49 in the CI group and 29 in the CIR group. Baseline characteristics (age, sex, clinical stage, cardiopulmonary function) were balanced between groups. During neoadjuvant therapy, the CI group had significantly lower incidences of grade 3 and grade 4 leukopenia/neutropenia (15/49 vs. 15/29, P = 0.025), and lower incidences of grade 3 and grade 4 checkpoint inhibitor pneumonitis (CIP) (1/49 vs. 8/29, P = 0.002). All CI group patients achieved R0 resection after 1-3 neoadjuvant cycles versus 24/29 in the CIR group (P > 0.05). The CIR group showed higher major pathological response (including pathological complete response) rates (16/24 vs. 10/49), though statistically non-significant (P = 0.121). No significant differences were observed in 5-year progression-free survival or overall survival. Adding concurrent radiotherapy to neoadjuvant chemoimmunotherapy increased hematologic toxicity and CIP in resectable locally advanced ESCC patients, without conferring survival benefits.