Treatment results and late complications of 556 patients with locally advanced nasopharyngeal carcinoma treated with radiotherapy alone

The aim of this study was to investigate the outcome in 556 patients with locally advanced nasopharyngeal carcinomas treated by radiation therapy alone. We observed 556 patients with stage T3-4 and N0-3 carcinoma who were treated by conventional radiotherapy alone between January and December 1999. The total dose delivered to the nasopharynx was 66-80 Gy over 6.5-8 weeks and to the neck lymph nodes 60-70 Gy over 6-7 weeks. The 5-year actuarial overall survival rate (OS) reached 66.41%. The OS was higher among stage T3 patients than among stage T4 patients (69.12% vs 58.96%, p = 0.0359). Among patients with stage N0, N1, N2 and N3 disease, the OS was 73.98%, 65.96%, 57.58% and 29.39%, respectively (p = 0.0009). Differences in disease-free survival, locoregional control rate and metastasis-free survival rate among each N stage were statistically significant, although this was not true of differences between stage T3 and T4 disease. Multivariate analysis showed that gender, age, T stage and N stage were significant prognostic factors for 5-year overall survival, disease-free survival, locoregional control and metastasis-free survival. We found that N stage is the dominant prognostic indicator for patients with locally advanced nasopharyngeal carcinoma receiving conventional radiation therapy alone, and that T stage was only a secondary correlative factor.