Interim results from a prospective multicenter phase II trial of stratified treatment of localized cervical esophageal squamous cell carcinoma induced by neoadjuvant immunotherapy plus chemotherapy (SCENIC trial).
Authors: Li Chunguang , Liu Jun , Zhang Ming , Zhang Hong , Su Yuchen , Yang Yang , Liu Zhichao , Shao Jinchen , Zhu Li , Sun Yifeng , Hua Rong , Li Bin , Li Zhigang 
Published: August 2024

e16089 Background: Definitive concurrent chemoradiotherapy (dCRT) is the standard treatment for cervical esophageal squamous cell cancer (CESCC). However, salvage esophagectomy poses significant technical challenges in dCRT failures, and optimizing patient selection for dCRT remains an unsolved concern. In this context, we propose a stratified screening strategy by incorporating induction immunochemotherapy, aiming to identify suitable candidates for organ-sparing dCRT and timely surgical treatment. Methods: This prospective multicenter interventional phase II study (ChiCTR2200057732) enrolled patients with clinical stage T2-4NanyM0 (AJCC TNM 8th) resectable CESCC. Eligible participants received induction therapy of intravenous PD-1 inhibitor tislelizumab (200mg, day 1) plus nab-paclitaxel (100 mg/m2, day 1,8,15) and carboplatin (area under curve of 5 mg/mL/min, day 1) of each 21-days cycle, for two cycles. Treatment response was evaluated 4 weeks after the completion of induction therapy, according to the criteria of the CROC trial: Grade 1, remarkable response (RR); Grade 2, limited partial response (LPR); and Grade 3, poor response (POR). Stratified patients would receive different follow-up treatments: dCRT was administered to RR patients, and radical surgery was performed in LPR and POR patients. Tislelizumab was maintained after dCRT in RR patients, and the postoperative adjuvant therapy was dependent on the doctors in the surgery groups. The primary endpoint was the 2-year event-free survival with a planned enrollment of 36 patients in this study. Results: From Jul 2022 to Jan 2024, 28 patients were enrolled. Of these, 22 patients completed the full two-cycle induction therapy and response evaluation. The response after induction immunochemotherapy were RR in 50.0% (11/22), LPR in 31.8% (7/22), and POR in 18.2% (4/22). All of the RR population underwent subsequent dCRT. Among 11 non-RR patients, only 7 cases received esophagectomy, other 4 selected dCRT according to their will. Up to Jan 2024, the median follow-up was 11.0 months (3.5-17.7), all of the RR patients with dCRT were in disease-free survival, 1 LPR and 1 POR patients received dCRT had progression in the primary lesion, and 4 patients underwent surgery had locoregional or distant recurrences. Overall, 24 patients (96%) had any-grade treatment-related adverse events with the most common being leukocytopenia. Four patients (16%) had adverse events of grade 3 or worse, and no treatment-related death occurred. Conclusions: The 1-year survival of RR followed by dCRT appears promising compared to historical data. The strategy of induction immunochemotherapy showed effective in identifying candidates suitable for dCRT in patients with resectable CESCC. Enrollment is ongoing. Clinical trial information: ChiCTR2200057732.