Unilateral neck treatment with either surgery and/or radiotherapy for squamous cell carcinoma for the tonsil.

Abstract

INTRODUCTION Strategies for treatment of tonsil carcinoma are under active investigation. Limiting surgical and radiation treatment volumes to the primary tumor and ipsilateral neck in appropriately selected patients is one such approach. Here, we present our institutional experience with treatment through ipsilateral surgical or radiotherapeutic neck management. METHODS We retrospectively reviewed our institutional database of patients with tonsil carcinoma treated from 2012 to 2020. Patients were included for analysis if they received definitive radiation therapy (RT), definitive surgery (S), or surgery with post-operative radiation therapy (S-PORT) and whose treatment volumes were limited to the primary tumor and involved/elective ipsilateral neck. Patients who received radiation and/or surgery to the contralateral neck (including those with bilateral nodal involvement), as well as patients with metastatic disease, were excluded. Clinical factors including T- and N-stage (AJCC 7th edition), and HPV status (by p16 and/or HPV DNA PCR) were recorded, as were pathologic factors (when applicable) including margin status, extracapsular extension (ECE), lymphovascular invasion (LVSI), and perineural invasion (PNI). Overall survival (OS), progression free survival (PFS), and locoregional control (LRC) at 2 years were estimated using the Kaplan-Meier method. RESULTS In total, 71 patients were treated with unilateral neck approaches: S (n=49), RT (n=10), and S+PORT (n=12). Among these patients, 32, 36, and 3 had T1, T2, and T3 disease, respectively. N-stage was N0, N1, N2a, N2b, and N3 in 22, 20, 5, 23, and 1 patient(s), respectively. Concurrent chemotherapy was administered in 12 patients. From those with recorded risk factors, 86% were HPV-positive, 20% had LVSI, 7% had PNI, 13% had ECE, and 5% had positive margins. From a median follow-up of 27 months, local, regional, and distant failures occurred in 5, 6, and 5 patients, respectively. No contralateral neck failures were recorded. At 2 years, OS, PFS, and LRC were 92% (95% CI 85-99%), 85% (95% CI 75-95%), and 88% (95% CI 80-98%), respectively. CONCLUSIONS In patients with early T-stage tonsil carcinoma, treatment of the primary tumor and ipsilateral neck is associated with acceptable OS, PFS, and LRC. In this population, the risk of contralateral neck failure is likely very low regardless of primary treatment modality. Additional prospective studies are needed to determine the impact of limiting treatment extent to the unilateral neck.