Clinical Outcomes in Patients With T4b Esophageal Squamous Cell Carcinoma: A 10‐Year Single Institution Experience

Esophageal squamous cell carcinoma (ESCC) with adjacent structure invasion (T4b), affecting areas such as the aorta, vertebral body, or trachea, is associated with a poor prognosis, and the optimal treatment strategy remains unclear. While chemotherapy is considered standard, radiation therapy is often avoided due to the risk of severe complications, including tracheoesophageal fistula. This 10-year cohort study investigated clinical outcomes and prognostic factors in patients with T4b ESCC. From October 2011 to May 2022, 471 ESCC patients were diagnosed at our institution, of whom 130 (27%) had T4b disease. First-line treatments included definitive chemoradiotherapy (n = 82), chemotherapy alone (n = 15), radiotherapy alone (n = 5), immunotherapy clinical trials (n = 7), palliative surgery (n = 2) and best supportive care (n = 19). Patients treated with definitive chemoradiotherapy demonstrated significantly longer overall survival compared with those receiving monotherapy. The mean survival was 24.2 months in the chemoradiotherapy group, versus 4.2 months with chemotherapy alone and 8.5 months with radiotherapy alone (p < 0.001). Esophageal fistula developed in 22 patients (16.9%), with 5 cases identified at diagnosis and 17 occurring during follow-up. Chemotherapy alone was associated with a significantly higher risk of fistula formation compared with chemoradiotherapy (adjusted hazard ratio = 11.22, p = 0.01). The presence of a fistula was correlated with worse survival outcomes (median survival of 8.9 months versus 12.2 months, p = 0.03). These findings suggest that definitive chemoradiotherapy may enhance survival in T4b ESCC patients.