Preoperative chemotherapy combined with PD-1 inhibitor in locally advanced operable or potentially resectable esophageal squamous cell carcinoma: A real world study.

Abstract

e16010 Background: Preoperative therapy of esophageal squamous cell carcinoma (ESCC) is stepping into the era of combined therapy with PD-1 inhibitor after the success of PD-1 antibodies in the first-line and second-line treatment for advanced ESCC. This single center study retrospectively analyzed the efficacy and safety of preoperative chemotherapy combined with PD-1 antibody in patients with locally advanced operable or potentially resectable ESCC in the real world. Methods: The study enrolled operable or potentially resectable locally advanced ESCC patients treated with preoperative chemotherapy combined with PD-1 inhibitor in our center from April 2020 to December 2020. The treatment regimen were 2 to 4 cycles of paclitaxel liposome (135̃175 mg/m2) or albumin paclitaxel (180mg/m2) plus nedaplatin (75mg/m2) or lobaplatin (30mg/m2) combined with PD-1 inhibitors (toripalimab 13/20, sintilimab 3/20, pembrolizumab 2/20, camrelizumab 1/20, tislelizumab 1/20) with standard therapeutic dose followed by tumor response assessment and surgery. The primary end point were safety, tumor response and complete pathological response (pCR) rate. Results: A total of 20 patients including 17 males and 3 females, of which median age was 65 and 85% were stage III-IVA (AJCC 8th), were included in the study. Of all the patients, 18 patients accomplished 2 cycles of therapy and had safety assessment, 13 patients underwent surgery, 2 patients were waiting for operations and 2 patients achieving partial response rejected surgery and were prepared for radical chemoradiotherapy. Treatment-related adverse events exceeding grade 3 levels included leukopenia 5.6% (1/18), neutropenia 16.7% (3/18), thrombocytopenia 5.6% (1/18), and immune hepatitis 5.6% (1/18). There was no severe surgery-related complication. Objective response rate (ORR) was 70.6% (12/17), and disease control rate (DCR) was 100% (17/17). R0 resection rate was 92.3% (12/13), the pCR rate was 15.4% (2/13), and 61.5% (8/13) of the patients had downstaged to the ypT1-2N0M0 I stage. One patient finally reached a pCR after switching to preoperative chemoradiotherapy because of progression after treatment of chemotherapy and PD-1 inhibitor. Conclusions: Preoperative chemotherapy combined PD-1 inhibitor treatment was well tolerated and had high efficacy in locally advanced operable and potential resectable ESCC. Since the study included some potentially resectable patients with late staging, the pCR rate may be lowered. The further study aims to find the efficient biomarker including PD-L1 expression and CD8+ T cell infiltration. Moreover, well-designed randomized prospective trials for better evidence are required.