Abstract
BACKGROUND: To evaluate the efficacy and safety of chemo-immunotherapy combined with residual lesions irradiation of advanced stage esophageal squamous cell carcinoma. METHODS: Treatment-naïve patients with radiologically and histologically confirmed advanced or metastatic squamous-cell esophageal carcinoma were enrolled. Participants received four cycles of the TP regimen combined with the PD-1 inhibitor sintilimab. Patients who completed four cycles of chemo-immunotherapy with stable disease (SD) or partial response (PR) subsequently received 50 Gy of radiation in 25 fractions for residual tumors. Maintenance sintilimab therapy was administered every 21 days for up to 31 cycles or until disease progression or intolerable toxicity occurred. RESULTS: A total of 39 patients were enrolled in this study, of whom 30 were evaluable for efficacy and toxicity. The complete response (CR) rate was 6.7% (2/30), the partial response (PR) rate was 53.3% (16/30). The median depth of response (DpR) was 34.5% for chemo-immunotherapy and increased to 64.0% after radiotherapy. The progression-free survival (PFS) was 16.4 months, while overall survival (OS) has not yet been reached. CONCLUSIONS: Chemo-immunotherapy followed by radiotherapy for residual tumors and maintenance sintilimab, demonstrated high response rates, prolonged PFS, and tolerable toxicity as a first-line treatment for patients with advanced or metastatic esophageal squamous-cell carcinoma.