[Patterns of recurrence in patients with stage Ⅲ thoracic esophageal squamous cell carcinoma after radical resection]

Objective: To evaluate the patterns of recurrence and their value on target delineation for postoperative radiotherapy (RT) in patients with stage Ⅲ thoracic esophageal squamous cell carcinoma (ESCC) after esophagectomy. Methods: 395 patients (302 male and 93 female) of stage Ⅲ thoracic ESCC after radical resection were enrolled in this study. Among them, 375 patients were treated with two-field and other 20 with three-field esopahgectomy. 97 patients were treated with surgery alone, 212 with adjuvant postoperative chemotherapy (CT), 56 with radiotherapy (RT) and 30 with CT plus RT. Diagnosis of recurrence was primarily based on CT images, some of which were biopsy confirmed. The location and patterns of tumor recurrence were analyzed. Results: The overall failure rates was 75.7% (299/395). Locoregional recurrence (LR) was found in 48.4% of the patients, distant metastasis (DM) in 16.2%, and LR plus DM in 4.3%. There were 208 patients occurred with LR, 26.9% (56) recurred in supraclavicular/neck (51 in supraclavicular), 69.7% (145) in mediastinum (88.7% in upper-mediastinum), and 19.7% (41) in upper abdomen (38 in para-aortic lymph node). Chi-square test and logistic multivariate regression analysis showed that TNM stage and adjuvant therapy were significantly associated with LR (P<0.05). Postoperative RT reduced LR (mainly LR in mediastinum), but postoperative CT did not decrease LR. Conclusions: The recurrence rate is very high in stage Ⅲ thoracic ESCC patients, LR is the main pattern of failure. TNM stage is one of the most important factors for LR. Postoperative radiotherapy can reduce LR but postoperative chemotherapy does not decrease LR. Upper-mediastinum is the most common site of recurrence, followed by supraclavicular and para-aortic regions; these areas should be considered as the key target of postoperative radiotherapy.