Incidence and outcome for patients with occult lymph node involvement in T1 and T2 oral squamous cell carcinoma: a prospective study

The evidence base to inform the decision making process in patients with early stage oral cancer and a clinical and radiological N0 neck remains insufficient to answer the question when it is safe to “watch and wait” and when to proceed with a selective neck dissection.

A total of 327 consecutive cases of histopathologically staged T_1–2, N_0–1 and M₀, but clinically N_0, squamous cell carcinoma of the tongue were prospectively analysed. Univariate and multivariate analyses were used for statistical analysis and are represented as Kaplan-Meier analyses or Cox proportional hazard regression analysis.

In 61 patients (18.65%) lymph node involvement was found in the histopathological processing. The mean survival of all patients was 73.3 ± 48.6 months. The 2-year and 5-year overall survival rates of all patients were 87.5% and 68.4%, respectively. The 2-year and 5-year survival rates for stage N₀ were 89.1% and 70.7% compared to 83.3% and 62.9% in N₁ situations. The 2-year and 5-year survival rates for stage T₁ were 87.9% and 73.6% compared to 87.2% and 65.3% in stage T₂, respectively_. The time to recurrence in stage N₀ was 35.1 ± 30.5 months compared to 25.63 ± 24.6 months in cases with N₁ disease. Stage T₁ was associated with a time to recurrence of 38.1 ± 33.9 months compared with 27.2 ± 22.7 months in patients classified T₂.

Variables found to be strongly associated with survival in the univariate analysis included older age, higher tumour and N stage, and grading. Age, tumour stage (p = 0.011, 95% CI, 1.09 to 2.0), nodal stage (p = 0.038, 95% CI, 1.02 to 2.07), and recurrence were independently and significantly associated with survival in the multivariate analysis.

This confirms a high overall disease free survival for patients with T1 and N0 treated with single modality surgery and in common with the literature confirms the poor impact on prognosis of the N positive neck.