Prognostic value of lymph node involvement in oral cancers: a study of 137 cases.

OBJECTIVE: The aim of this study was to assess the prognostic value of lymph node involvement in patients with squamous cell carcinoma of the oral cavity.

STUDY DESIGN: Retrospective study of 137 patients with T4 squamous cell carcinoma of the oral cavity treated by surgery and radiotherapy (84 N0, 23 N1, 16 N2,14 N3). Twenty-three patients in the N0 group had a history of surgery or radiotherapy. One hundred fourteen patients underwent limited or radical neck dissection unilaterally or bilaterally.

METHODS: The histological charts were reviewed and correlated with preoperative lymph node clinical stage. The local failure rate and the overall survival curves were calculated with respect to clinical and histological stages. The causes of death were analyzed.

RESULTS: No evidence of lymph node metastasis was found in 47.4% of cases (54 of 114 patients). Among the node-positive (N+) patients, 39 had rupture of the lymph node capsule (R+). In the N0 group, 27.8% of patients were N+. Regional control rates after surgery and radiotherapy were 95% at 1 year and 85.4% at 5 years. The local failure rates were 6% in N0, 8.7% in N1, 31.2% in N2, 51.7% in N3, 9% in node-negative (N-), and 29% in N+R+ patients. The overall survival rates at 3 and 5 years were, respectively, 44.7% and 34.8% in the N0 group, 37.7% and 37.7% (same rate at 3 and 5 years) in the N1 group, and 31.2% and 15.8% in the N2 group. None of the patients in the N3 group survived beyond 2 years. The overall survival rates at 5 years were 42.8% and 17.5% in the N- and N+ groups, respectively.

CONCLUSIONS: In patients with locally advanced tumors (T4), clinical nodal status and histological nodal invasion were key prognostic factors. The presence of occult metastases in the N0 group justifies routine neck dissection.