Anterior tongue cancer and the incidence of cervical lymph node metastases with increasing tumour thickness: should elective treatment to the neck be standard practice in all patients?

BACKGROUND: There is an increasing risk of cervical lymph node metastases as tumour thickness increases in patients with anterior tongue squamous cell carcinoma (SCC). The role of elective neck treatment in early anterior tongue cancer in unclear.
METHODS: Patients diagnosed with anterior tongue cancer and treated with glossectomy +/- neck dissection were identified. The aim was to document the incidence of pathological lymph node metastases and outcome with increasing tumour thickness. The Cox proportional hazards model was used to identify prognostic factors. Survival curves were calculated using the Kaplan-Meier method.
RESULTS: Between 1980 and 2002 99 patients (63 male and 36 female) with anterior tongue SCC were treated at Westmead Hospital, Sydney, and had a documented tumour thickness. Median age at diagnosis was 63 years (23-89 years). Median follow up was 37 months (6-205 months). Sixty-three patients underwent partial glossectomy and neck dissection. Thirty-six underwent partial glossectomy only. At the time of presentation 45/63 (71%) were clinically node negative. Using tumour thickness < or = 5 mm versus > 5 mm the incidence of nodal metastases was 8% versus 51% (P = 0.007). On multivariate analysis pathological nodal involvement and advanced stage both significantly predicted survival. The 2-year disease-free survival difference based on tumour thickness (< or = 5 mm vs > 5 mm) was 76% versus 65% (P = 0.47).
CONCLUSIONS: Elective treatment to the ipsilateral neck is not indicated in all patients with anterior tongue cancer. However, for patients with a tumour thickness > 5 mm it is recommended that they undergo treatment to the ipsilateral neck in the form of a supraomohyoid neck dissection.