Clinical nodal staging of T1-2 tonsillar squamous cell carcinoma stratified by p16 status and implications for ipsilateral neck irradiation

Background and Purpose: Previous studies have reported <5% incidence of contralateral nodal metastasis in patients with T1-2 tonsillar squamous cell carcinoma. We analyzed the nodal staging of T1-2 tonsillar squamous cell carcinoma stratified for p16 status, a marker of human papillomavirus positivity. Materials and Methods: Clinical and radiographic nodal staging and p16 status of 41 T1-2 tonsillar squamous cell carcinoma patients who were treated between January 2002 and June 2009 were retrospectively analyzed. Patients with a history of prior head and neck cancer, synchronous cancers, base of tongue or soft palate invasion, or distant metastases at diagnosis were excluded. Results: Of the 41 patients, 28 (68.2%) had p16+ tumors and 13 (31.7%) had p16- tumors. Seven patients (17.0%) presented with contralateral cervical nodal disease, all of whom had p16+ tumors. Furthermore, 25.0% of patients with p16+ tumors presented with contralateral cervical nodal disease compared with 0% of patients with p16- tumors. Conclusions: Patients with p16+ T1-2 tonsillar squamous cell carcinoma present with a higher incidence of contralateral nodal spread than those patients with p16- disease. This may have clinical implications when determining which patients are good candidates for ipsilateral cervical nodal irradiation.