Risk factors and treatment of contralateral neck recurrence for unilateral oral squamous cell carcinoma: A retrospective study of 1482 cases

Background: The aim of this study was to describe risk factors of contralateral neck recurrence (CLNR) and to identify its high-risk population after treatment for unilateral oral squamous cell carcinoma. Methods: Between June 1991 and June 2012, a total of 1482 eligible patients who were treated with radical surgery with or without adjuvant therapy were retrospectively reviewed. Results: The outcome assessment parameters were the rate of 5-year CLNR and the rate of disease-specific survival (DSS). In the entire study cohort, the 5-year CLNR rate was 4.1%. In a multivariate analysis, only extracapsular spread (ECS) status (hazard ratio [HR]: 12.978, 95% confidence interval [CI]: 1.328-126.829, P = 0.028) was an independent risk factor for 5-year CLNR. In addition, 5-year CLNR (HR: 36.410, 95% CI: 7.093-186.914, P < 0.001), T stage (HR: 3.475, 95% CI: 1.151-10.488, P = 0.027) and growth pattern (HR: 4.831, 95% CI: 1.776-13.140, P = 0.002) were independent risk factors for 5-year DSS. Patients with at least two risk factors were identified as a high-risk population for CLNR; these patients also had a poor prognosis. Elective contralateral neck dissection (ND) plus concurrent chemoradiotherapy (CCRT) can improve the 5-year DSS in these high-risk patients, but it does not decrease the 5-year CLNR rate. Conclusion: For low-and moderate-risk patients, contralateral neck observation should be considered sufficient if strict compliance with a cancer surveillance protocol is followed. However, whether high-risk patients benefit from contralateral ND plus adjuvant CCRT can only be answered in a prospective trial. (C) 2014 Elsevier Ltd. All rights reserved.