Patterns of lymphatic spread in thoracic esophageal cancer

The cervical nodes have been excluded from the category of regional nodes in cases of thoracic esophageal cancer in the present TNM classifications.

One hundred and forty-one patients with thoracic esophageal cancer who had undergone extensive radical lymphadenectomy were included in the study. The patterns of early lymph node metastasis from the disease, in terms of lymph node metastases from the intramural tumors or those found in patients with a single metastatic node, were studied. Prognostic significance of the removal of the positive nodes also was examined in relation to the metastatic sites.

Of the 47 patients with intramural cancer, only 21% had nodal metastases confined to the mediastinum, 11% had positive cervical nodes, and 23% had jumping metastases to the extramediastinal nodes. Of the 31 patients with a single metastatic node, 61% showed metastasis in a jumping fashion, and 19% had a positive node in the neck. Seventy-four (79.6%) of the 93 patients with vessel invasion also had lymph node metastases, whereas 20 (41.7%) of the 48 patients without vessel invasion had metastases to the lymph nodes (P < 0.001). The 5-year projected survival rate for patients with positive cervical nodes was 27%, with no significant difference in survival rate compared with that for patients with metastatic nodes in the mediastinum or the abdomen. The number of involved nodes was related significantly to outcome: The 5-year survival rates for the 45 patients with negative nodes the 66 patients with one to four positive nodes were 71.8 and 34.2%, respectively (P < 0.01), whereas none of the 27 patients with five or more positive nodes survived more than 3 years after the operation (P < 0.001).

The cervical nodes should be included in the category of regional nodes in cases of thoracic esophageal cancer on the basis of the patterns of early lymph node metastases and the prognostic significance of a lymphadenectomy for metastases to these nodes.