150. PATTERN OF LYMPH NODE RECURRENCE AFTER NEOADJUVANT CHEMORADIOTHERAPY AND MODIFIED EN BLOC ESOPHAGECTOMY.

Background Esophageal cancer is an aggressive malignancy with high incidence of lymph node metastasis and recurrence rate even after neoadjuvant treatment and radical resection. Previous study has shown that modified en bloc esophagectomy (mEBE) improves survival for esophageal squamous cell carcinoma (ESCC) after neoadjuvant chemoradiotherapy (nCRT). In this study, we aim to investigate the pattern of lymph node recurrence after nCRT+mEBE. Methods The data of patients who received nCRT followed by curative surgical resection for ESCC were retrospectively reviewed. The mEBE includes 'mesophagus' dissection and bilateral recurrent laryngeal nerve node dissection, whereas conventional esophagectomy (CE) only requires periesophageal tissues dissection that were close to the esophagus. The pattern of recurrence, especially lymph node recurrence (cervical, upper mediastinum, infra-carina, and abdominal), were compared between CE and mEBE, with stratification according to pathological stage (ypT0N0 or not.) Results A total of 221 (CE, n = 181; mEBE, n = 40) patients were included. Mediastinal lymph node recurrence was noted in 16.0% and 7.5% of patients after CE and mEBE, respectively (p = 0.166). In ypT0N0 patients who received CE, 6.0% had upper mediastinum recurrence, whereas no mediastinal recurrence was noted after mEBE (p = 0.329). In non-ypT0N0 stage patients who received CE, 15.3% and 8.2% had upper mediastinum and infra-carina recurrences, compared to 12.0% and 0% after mEBE (p = 0.283). There cervical/abdominal recurrences were noted in 6.6%/7.2% and 15.0%/5.0% after CE and mEBE, respectively (p = 0.080/0.618). Conclusion Although there was no significant difference in lymph node recurrence pattern between mEBE and CE, we observed that (1) 6% of ypT0N0 patients developed mediastinal lymph node recurrence after CE, implying the possibility of understaging after CE; (2) no patients developed infra-carina lymph node recurrence after mEBE, suggesting the necessity of mesoesophagus dissection, and (3) high incidence of cervical lymph node recurrence even after mEBE, indicating that cervical dissection should be considered in selected patients. [ABSTRACT FROM AUTHOR]