Based on ctDNA-MRD Guided Adjuvant Treatment Escalation After Definitive Chemoradiotherapy for Unresectable Locally Advanced Esophageal Squamous Cell Carcinoma: a Study on Safety and Efficacy

Inclusion Criteria

• •1. Histologically confirmed locally advanced esophageal squamous cell carcinoma (ESCC), with clinical stage Ⅱ-Ⅳ unresectable disease (including unresectable cases, patients with surgical contraindications, or those who refuse surgery). According to the 8th edition AJCC staging system, the pretreatment clinical stage is defined as: cT1N2-3M0, cT2-4bN0-3M0; M1 disease is limited to non-regional lymph node metastases, excluding distant organ metastases.
• •2. No prior systemic therapy administered for the disease, and planned to receive definitive chemoradiotherapy (dCRT).
• •3. Having undergone 1021-gene large panel testing on tissue samples.
• •4. Aged 18-80 years old.
• •5. Expected overall survival ≥ 6 months.
• •6. ECOG performance status 0-1.
• •7. Normal blood biochemical parameters, with normal liver and kidney function.
• •8. Able to understand the study protocol, voluntarily participate in the study, and sign the informed consent form.
• •9. Good compliance, able to cooperate with specimen collection at all designated time points and provide relevant clinical data.