This multicenter, prospective Phase II study investigates a response-adapted organ-preservation strategy in patients with resectable esophageal squamous cell carcinoma (ESCC). Participants will receive two cycles of induction chemoimmunotherapy with sugemalimab, nab-paclitaxel, and cisplatin. Patients who achieve a major clinical response will receive definitive radiotherapy plus sugemalimab followed by maintenance sugemalimab, while non-major responders will undergo surgery-based treatment strategies. The study aims to evaluate the efficacy and safety of this tailored treatment approach, with the primary endpoint being 2-year progression-free survival. Secondary and exploratory objectives include survival outcomes, quality of life, nutritional status.