The clinical significance of subcarinal lymph node dissection in the radical resection of oesophageal cancer.

OBJECTIVES To explore the rule of subcarinal lymph node metastasis in thoracic oesophageal cancer and its clinical significance in the radical resection of oesophageal cancer. METHODS We retrospectively analysed 2223 patients with oesophageal cancer who were admitted to Henan Cancer Hospital during 2004-2011 and underwent surgery as the first treatment option. Routine subcarinal lymph node dissections were performed, and the sections from the resected lymph nodes were embedded in paraffin for routine pathological examination. RESULTS Subcarinal lymph node metastasis was observed in 200 patients (9%). Logistic regression analysis identified the following risk factors (P < 0.05): tumour location, depth of invasion into the oesophageal wall, tissue type, number of lymph node metastases, paraoesophageal lymph node metastasis (level 8 lymph nodes), left gastric cardiac lymph node metastasis. Unpaired t-test and χ(2)-test showed that more lymph node metastases, longer tumour length, deeper tumour invasion, middle oesophageal cancer, squamous-cell carcinoma, lower degree of differentiation, paraoesophageal lymph node metastasis and left gastric cardiac lymph node metastasis were associated with a higher frequency of subcarinal lymph node metastases (P < 0.05). Using the Kaplan-Meier method, recurrence and metastasis were shown to be more likely with solitary subcarinal lymph node metastasis than with solitary paraoesophageal lymph node metastasis (P = 0.001). CONCLUSIONS Tumour location, depth of invasion, pathological type, degree of differentiation and other factors are closely associated with subcarinal lymph node metastasis. Recurrence and metastasis after oesophageal dissection are more likely with subcarinal lymph node metastasis.