The impact of adjuvant therapies on patient survival and the recurrence patterns for resected stage IIa–IVa lower thoracic oesophageal squamous cell carcinoma

BACKGROUND: This study evaluated the impact of adjuvant therapies on patient survival and disease recurrence patterns to identify an effective adjuvant therapy for resected lower thoracic oesophageal squamous cell carcinoma (LTESCC). METHODS: Clinical data of 127 patients with stage IIa-IVa LTESCC with a minimum 2-year follow-up after oesophagectomy were analysed. The survival and recurrence patterns were compared among patients who received adjuvant radiotherapy, adjuvant chemotherapy, adjuvant chemoradiotherapy, or surgery alone. RESULTS: Eighty-eight patients (69.3%) were identified as having disease recurrence. The regional lymph node recurrence rate was 57.5%, and the recurrence rates were high in the lower neck, upper mediastinum, and upper abdomen. Compared to surgery alone, adjuvant radiotherapy or chemoradiotherapy significantly decreased the recurrence rate (p < 0.05). Adjuvant chemoradiotherapy significantly improved overall survival, disease-free survival, and locoregional recurrence-free survival compared to surgery alone (p = 0.01, 0.01, and 0.00, respectively). Pathologically positive lymph nodes (PPLNs) in the lower mediastinum represented a potential risk factor for cervical recurrence (HR 2.97, 95%CI 1.19–7.39). Multivariable analysis showed that postoperative radiotherapy (HR 0.30, 95%CI 0.13–0.68) and PPLNs in the upper mediastinum (HR 3.72, 95%CI 1.30–10.67) were independent risk factors for upper mediastinal recurrence, while postoperative radiotherapy (HR 0.37, 95%CI 0.16–0.85) and PPLNs in the abdomen (HR 2.57, 95%CI 1.12–5.92) were independent risk factors for abdominal recurrence. CONCLUSION: Adjuvant chemoradiotherapy was the most effective adjuvant therapy for resected stage IIa-IVa LTESCC. The lower neck, upper mediastinum, and upper abdomen were high-risk regions for postoperative radiotherapy. The regions of PPLNs may be important factors for individual targets.