Clinical value of lymph node dissection for stage T1b mid-thoracic esophageal squamous cell carcinoma

Surgery remains the mainstay of treatment for esophageal squamous cell carcinoma (ESCC), during which lymph node (LN) dissection, especially recurrent laryngeal nerve (RLN) LN dissection, is particularly important and challenging. This study aimed to investigate the LN metastasis of stage T1b mid-thoracic ESCC and explore the clinical value of RLN LN dissection.

The clinicopathological data of 254 patients with stage T1b mid-thoracic ESCC who underwent the McKeown procedure ("tri-incisional esophagectomy") and three-field LN dissection (3FD) at Fujian Cancer Hospital from January 2010 to December 2015 were retrospectively analyzed. The value of LN dissection (especially RLN LNs) was evaluated by calculating the metastasis rate of each LN station. The efficacy index (EI) of the dissection was calculated by multiplying the frequency (%) of metastases to a station and the 5-year survival rate (%) of patients with metastases to that station, and then dividing by 100.

The stage T1b mid-thoracic ESCC had the highest rate of metastasis in the paracardiac LNs (4.3%), followed by RLN LNs (2.8%) and the left gastric artery LNs (2.8%). The 5-year survival rate was highest in patients who received lesser gastric curvature LN dissection (100%), followed by patients who underwent right RLN LN dissection (80%), and was 50% in patients who had undergone dissection of the left RLN LNs, upper paraesophageal LNs, subcarinal LNs, and left gastric artery LNs, respectively. In addition, dissection of the right RLN LNs had the highest EI value (2.2), followed by the dissection of LNs along the lesser curvature of the stomach (1.6) and left gastric artery LNs (1.4).

Right RLN LNs have a metastasis rate only lower than that of the paracardiac LNs, but could be the most valuable location for performing dissection.