Abstract 92P
Background
This study aimed to evaluate the efficacy and safety of preoperative PD-1 inhibitor tislelizumab combined with CRT in unresectable esophageal squamous cell carcinoma (ESCC).
Methods
This is a single-arm, phase II trial, planned to enroll 30 patients. Eligibility criteria include histologically confirmed unresectable thoracic ESCC stage at cT4bNxM0 (AJCC 8th). Radiotherapy was delivered to a total dose of 50Gy/25f, concurrently with cisplatin (25 mg/m2) and nab-paclitaxel (100 mg) (QW, at least 3 cycles). Then followed by two cycles of tislelizumab (200 mg, Q3W), cisplatin (75 mg/m2, Q3W) and nab-paclitaxel (150 mg/m2, Q3W). If curative resection was considered, esophagectomy was performed within 4 weeks. Patients with pathologically residual disease would receive tislelizumab (200 mg, Q3W) for 1 year. The primary endpoint is 1-year progression free survival rate.
Results
From December 2021 to July 2022, 21 patients were enrolled. 16 patients completed chemoradiotherapy and received immunochemotherapy. Reasons for 5 patients who did not receive immunochemotherapy included patient refusal (n=1), progressive disease (n=1), esophageal fistula (n=2), waiting for immunochemotherapy (n=1). Finally, 13 patients proceeded to surgery, with R0 resection rate of 100%. Reasons for not undergoing surgery after immunochemotherapy were esophageal mediastinal fistula (n=1), surgery delay due to COVID-19 epidemic (n=2). The pCR and MPR rate was 61.5% (8/13) and 76.9% (10/13). G1, G2, G3 immune related pneumonia occurred in 3 patients, respectively. ≥G3 AEs occurred in 9 (42.9%) patients. Postoperative complications included anastomotic fistula (2/13), pleural effusion (2/13), pneumonia (1/13), myocardial damage (1/13), delayed wound healing (1/13).
Conclusions
Chemoradiotherapy followed by immunochemotherapy might be a useful conversional treatment option for unresectable ESCC. Esophagectomy after this could be safe with acceptable complications for unresectable locally advanced ESCC.
Clinical trial identification
ChiCTR2100054327.
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.