Prediction of prognosis by the extent of lymph node involvement in squamous cell carcinoma of the thoracic esophagus

Objectives: Current criteria of the N-category in the TNM staging system for carcinoma of the esophagus needs further subgrouping due to its simplicity in mixing together patients with different prognosis, Method: A retrospective cohort study of 186 patients (176 men and ten women; mean age, 59.9 years) with squamous cell carcinoma (SCC) of the thoracic esophagus who underwent esophagectomy followed by two-field lymphadenectomy and cervical lymph node sampling between 1992 and 1999 was conducted. A proposed N-category which involved dividing the nodal status into NO (no nodal involvement), N1 (less than or equal to4 nodes or less than or equal to 20% nodal involvement), and N2 (>4 nodes, or >20%, or non-regional nodal involvement) subgroups was used for survival analysis. Results: The overall 5-year cumulative survival rate was 27%. Lymph node metastases were identified in 101 (53.3%) patients. Cumulative survival rates were 46% at 4 years in the NO group and 21% at 4 years in the N1 group, whereas no patients in N2 group survived longer than 3 years (P < 0.01). A multivariable analysis revealed that independent prognostic factors included the depth of tumor invasion (P < 0.01), nodal involvement (P < 0.01), and organ metastasis (P < 0.01). Conclusion: In addition to the location of nodes, the extent of nodal involvement in SCC of the thoracic esophagus also plays an important role in prognosis prediction. (C) 2001 Elsevier Science B.V. All rights reserved.