A randomized clinical trial comparing prophylactic upper versus whole-neck irradiation in the treatment of patients with node-negative nasopharyngeal carcinoma.

Background: This study sought to compare the clinical outcomes of upper versus whole-neck prophylactic irradiation in the treatment of patients with node-negative nasopharyngeal carcinoma (NPC).

Methods: Between November 2005 and June 2012, 301 patients with node-negative NPC were randomly assigned to receive primary plus prophylactic upper neck irradiation (UNI, 153 patients) or primary plus whole-neck irradiation (WNI, 148 patients). Patients in both groups received irradiation to the primary tumor and the upper neck nodal regions, and patients in the WNI group also received irradiation to the lower neck. The main endpoint of the study was to compare the lower neck control rate between the 2 groups.

Results: With a median follow-up period of 39 months (range, 6-84 months), no patient in either group had a cervical node relapse. The overall survival at 3 years was 89.5% (95% confidence interval [CI] = 84.1%-95.0%) in the UNI group and 87.4% (95% CI = 81.4%-93.5%) in the WNI group (hazard ratio [HR] = 0.866, 95% CI = 0.41-1.82; P = .70). The 3-year relapse-free survival rate was 89.8% and 89.3% (95% CI = 84.2%-95.3% and 83.7%-94.8%, HR = 0.914, 95% CI = 0.42-2.00; P = .82), and the 3-year metastasis-free survival rate was 91.7% and 90.9% (95% CI = 87.0%-96.5% and 85.7%-96.1%) for the UNI and WNI groups, respectively (HR = 1.007, 95% CI = 0.44-2.32; P = .99).

Conclusions: Prophylactic upper neck irradiation is sufficient for patients with node-negative NPC.