Safety and oncological efficacy of bilateral recurrent laryngeal nerve lymph-node dissection after neoadjuvant chemoradiotherapy in esophageal squamous cell carcinoma: a propensity-matched analysis

Background: We sought to evaluate the safety and oncological efficacy of bilateral recurrent laryngeal nerve (RLN) lymph-node dissection (LND) in patients with esophageal squamous cell carcinoma (ESCC) who had undergone neoadjuvant chemoradiotherapy (nCRT). Methods: We retrospectively examined the records of ESCC patients who were judged to be ycN-RLN(-) following nCRT. Patients were divided into two groups according to the extent of LND [standard two-field LND (STL group) versus total two-field LND (TTL group)]. Only lower mediastinal and upper abdominal lymph nodes were removed in the STL group. In addition to the standard procedure, patients in the TTL group underwent resection of upper mediastinal lymph nodes located along the bilateral RLN. Using propensity score matching, 29 pairs were identified and compared with regard to perioperative complications, lymph-node metastases rates, overall survival (OS), and disease-specific survival (DSS). Results: No significant intergroup differences were identified in terms of in-hospital mortality and morbidity. Metastases to the RLN lymph nodes were identified in 20.7% (6/29) of TTL patients, being the only site of lymph-node metastases in three of them. TTL was associated with lower upper mediastinal lymph-node recurrence rate (6.5%) compared with STL (21.5%, p = 0.134), although the overall recurrence rate was similar (STL, 44.8% versus TTL, 46.4%). No significant intergroup differences were also evident with regard to 3-year DSS and OS rates. Conclusions: RLN LND can be safely performed in ESCC patients who had undergone nCRT, ultimately resulting in an improved local control, and should be practiced as part of the surgical routine.