Overview
The primary objective is to determine whether pretreatment-to-posttreatment changes in circulating multigene methylation levels correlate with objective response rates (ORR) assessed by contrast-enhanced CT/MRI and levels of serum tumor markers. Secondary endpoints include: (a) time-dependent association between methylation fluctuation patterns and progression-free survival (PFS), (b) comparative diagnostic accuracy of methylation indices versus conventional biomarkers, and (c) feasibility of using methylation thresholds to guide adaptive therapy modification.
Eligibility
Inclusion Criteria:
Age at initial diagnosis: 18-75 years (inclusive) Confirmed diagnosis: Histologically proven esophageal carcinoma with complete medical records, including (a) definitive pathological diagnosis report, (b) TNM staging per AJCC 8th edition criteria Cancer history: No prior malignancies at other anatomical sites (excluding cured non-melanoma skin cancers/carcinoma in situ) Metastasis status: Radiologically confirmed absence of distant metastases in liver, lungs, or other organs via contrast-enhanced CT/MRI and whole-body bone scan within 4 weeks before enrollment Treatment-naïve status: No previous exposure to (i) esophageal resection surgery, (ii) systemic chemotherapy, (iii) thoracic radiation therapy (\>10 Gy), or (iv) PD-1/PD-L1 immune checkpoint inhibitors
Exclusion Criteria:
Life expectancy \<6 months (as assessed by ECOG score ≥4 or Palliative Performance Scale ≤30%) Cognitive/psychiatric conditions: a. Legally incapacitated individuals without legal guardians, b. Active psychotic disorders (e.g., schizophrenia, bipolar disorder) or dementia (MMSE score \<24) Investigator-determined exclusions