Risk factors for lymph node metastasis of the left recurrent laryngeal nerve in patients with esophageal squamous cell carcinoma

Background The factors for left recurrent laryngeal nerve (RLN) lymph node (LN) metastasis have important guiding significance for whether the left RLN LNs should be dissected in patients with esophageal squamous cell carcinoma (ESCC), but few studies are currently available. To analyze the risk factors of LN metastasis of the left RLN area and to assess which LNs should be dissected in ESCC. Methods This was a retrospective study of patients who underwent McKeown minimally invasive esophagectomy (MIE) (no neoadjuvant therapy) at Tianjin Medical University Cancer Institute and Hospital (from January 2016 to December 2019). The detection of left RLN LNs using enhanced computed tomography (CT) was compared with the pathological examination. Results Of the total 94 participants, 43 had LN metastasis. The metastatic LNs were mainly located next to left (18.1%) and right (14.9%) RLN, and the left gastric artery (13.8%). Tumor size, LN size, tumor invasion (T stage), N stage, and tumor node metastasis (TNM) stage were associated with left RLN LNs metastasis, while LN size was the only independently associated factor [odds ratio (OR) =1.569, 95% confidence interval (CI): 0.259-1.956, P=0.0012]. The area under receiver operating characteristic (ROC) curve (AUC) reached 0.877, with 64% sensitivity and 75% specificity using a cutoff of 5.5 mm LN size. Conclusions The size of left RLN LN is independently associated with metastasis. Left RLN LNs >5.5 mm at CT examination are more likely to be positive and should probably be dissected.