Objective: To analyze the pattern of lymphatic metastasis in middle thoracic esophageal squamous cell carcinoma (ESCC) with different T staging and to investigate the clinical value of para-recurrent laryngeal nerve lymphadenectomy.
Methods: Clinicopathological data of 717 patients with middle thoracic ESCC undergoing Mckeown esophagectomy plus three-field lymph node dissection in Fujian Provincial Hospital from January 1999 to December 2007 were analyzed retrospectively. Lymph node metastatic rates of different T stages were calculated. Clinical value of each station lymphadenectomy, especially the para-recurrent laryngeal nerve lymphadenectomy, was evaluated by the efficacy index (EI, cross product of one station metastatic rate and 5-year survival of patient with positive lymph nodes of above station).
Results: Rates of lymph node metastasis were 29.0% (18/62), 61.1% (91/149) and 64.8% (328/506) in stage T1, T2 and T3 patients respectively. Despite T staging, metastatic rates of right para-recurrent laryngeal nerve lymph node (rRLN LN) were 21.0% (13/62), 28.9% (43/149) and 29.4% (149/506) in stage T1, T2 and T3 patients respectively, which was the most common among all lymph node stations. Metastatic rates of left para-recurrent laryngeal nerve lymph node (lRLN LN) were the second, with 8.1% (5/62), 17.4% (26/149) and 24.7% (125/506) in stage T1, T2, T3 patients respectively. Follow-up period lasted more than 5 years. The 5-year survival rates of positive rRLN LN were 53.8%, 39.5% and 32.2% in stage T1, T2 and T3 patients respectively, whose EI values were 11.3, 11.4 and 9.5 respectively. The 5-year survival rates of positive lRLN LN were 40.0%, 34.6% and 40.0% in stage T1, T2 and T3 patients respectively, whose EI values were 3.2, 6.0 and 9.9 respectively.
Conclusions: Bilateral para-recurrent laryngeal nerve lymph nodes are the common sites of metastasis in middle thoracic esophageal squamous cell carcinoma. Right para-recurrent laryngeal nerve lymphadenectomy is of high clinical value despite the T staging. Left para-recurrent laryngeal nerve lymphadenectomy has better efficacy in stage T2 and T3 patients, but is limited in stage T1 patients.