Dynamic ctDNA Monitoring in Neoadjuvant Therapy for Esophageal Squamous Cell Carcinoma

This study aims to enroll 100 Chinese patients with stage II-III (potentially) resectable esophageal squamous cell carcinoma.

Tumor tissue samples will be collected from the subjects before neoadjuvant therapy for whole-exome sequencing (WES). Based on the WES results, personalized ctDNA detection panels will be designed (referred to as panel 1) for blood-based multiplex PCR-NGS testing. Blood samples will be collected at baseline (T0), after the first cycle of treatment (T1), after the second cycle of treatment (T2), after the third cycle of treatment (T3), and after the fourth cycle of treatment (T4) for monitoring.

Intraoperative tumor tissue will be collected. For patients with tumor cell content ≥20%, WES will be performed, and a personalized ctDNA detection panel (referred to as panel 2) will be designed based on the WES results. For patients with tumor cell content <20%, panel 1 will continue to be used for blood-based multiplex PCR-NGS testing. Blood samples will be collected before surgery (T5), 3-7 days after surgery (T6), and during the adjuvant therapy period (T7-TN) for ctDNA monitoring. MRD monitoring will be conducted every 3-6 months during follow-up, with dynamic recurrence monitoring until radiological recurrence or the end of the study. The stable detection limit for ctDNA monitoring is 0.02%.

It is expected to complete enrollment within 1 year. Clinical and pathological data, such as performance status, imaging, and serum markers (e.g., CEA), will be collected during the clinical trial. Follow-up will be conducted for 24 months, and data on treatment regimens, recurrence-free survival (RFS), overall survival (OS), adverse events (AE), etc., will be collected. Continuous observation will be conducted for up to 3 years.

Bioinformatics analysis will be performed on the data to construct mutation profiles. Statistical analysis will be conducted to establish the correlation between ctDNA positivity, mutation characteristics, and prognostic indicators. The ctDNA data analysis results will be linked to clinical management to ultimately improve clinical care.

Treatment regimen: Neoadjuvant therapy with cetuximab combined with albumin-bound paclitaxel and nedaplatin for 2-4 cycles:

Albumin-bound paclitaxel: 400mg, IV, on day 1, every 3 weeks; Nedaplatin: 80 mg/m2, IV, every 3 weeks; Cetuximab: 200mg, IV, on day 1, every 3 weeks.