Nodal yield and survival in oral squamous cancer: Defining the standard of care.

BACKGROUND

Elective neck dissection (END) is commonly used as a staging and therapeutic procedure for oral squamous cell carcinoma (SCC) at high risk of nodal metastases. The authors aimed to determine whether the extent of lymphadenectomy, as defined by nodal yield, is a prognostic factor in this setting.

METHODS

A retrospective database review identified 225 patients undergoing END with curative intent for oral SCC between 1987 and 2009. Nodal yield was studied as a categorical variable for association with overall, disease-specific, and disease-free survival in univariate and multivariate analyses.

RESULTS

Nodal yield <18 was associated with 5-year overall survival of 51% compared with 74% in those with nodal yield ≥ 18 (P = .009). Five-year disease-specific survival rates were 69% in those with <18 nodes and 87% in patients with ≥ 18 nodes (P = .022). Similar results were obtained for disease-free survival, with 5-year rates of 44% with <18 nodes versus 71% with ≥ 18 nodes (P = .043). After adjusting for the effect of age, nodal status, T stage, and adjuvant radiotherapy on multivariate analysis, nodal yield <18 was associated with reduced overall (hazard ratio [HR], 2.0; 95% confidence interval [CI], 1.1-3.6; P = .020), disease-specific (HR, 2.2; 95% CI, 1.1-4.5; P = .043), and disease-free survival (HR, 1.7; 95% CI, 1.1-2.8; P = .040). In the pathologically lymph node-negative subgroup (n = 148), similar results were obtained.

CONCLUSIONS

Nodal yield is an independent prognostic factor in patients undergoing END for oral SCC. These results suggest that an adequate lymphadenectomy in this setting should include at least 18 nodes.