Efficacy of postoperative neck irradiation for regional control in patients with pN0 oral tongue cancer: Propensity analysis.

Abstract

The purpose of this study was to investigate whether adjuvant radiotherapy (RT) is efficacious for regional control and survival in patients with pN0 oral tongue cancer. Clinicopathological features of 166 patients with pN0 oral tongue cancer were compared between those who underwent adjuvant RT to the neck (neck RT-positive) and those who did not (neck RT-negative). Study endpoints were isolated regional recurrence and 3-year regional recurrence-free survival (RRFS). Propensity score matching was also performed. Cox regression analysis did not reveal any significant predictor of isolated regional recurrence, including RT field. Three-year RRFS showed modest improvement in neck RT-positive group compared to neck RT-negative group before (92.2% vs 91.9%) and after propensity analysis (93.8% vs 83.3%), without statistical significance (log-rank P = .85 and .37, respectively). Despite more frequent unfavorable factors, the neck RT-positive group had a comparable oncologic outcome to the neck RT-negative group, suggesting that a marginal benefit in regional control might be expected from extending the RT field to the neck for pN0 oral tongue cancer.