Very accelerated radiotherapy or concurrent chemoradiotherapy for N3 head and neck squamous cell carcinoma: Pooled analysis of two GORTEC randomized trials.

Objective: To analyze the outcome of N3 patients treated with very accelerated radiotherapy (VART) or different schedules of concurrent chemoradiotherapy (CRT) within two phase III trials.

Patients And Methods: Data of 179 patients with N3 HNSCC from two GORTEC randomized trials (96-01 and 99-02) were pooled. Patients received either VART: 64.8Gy/3.5weeks or one of the 3 following CRT regimens: Conventional CRT: 70Gy/7weeks+3 cycles carboplatin-5FU; Moderately accelerated CRT: 70Gy/6weeks+2 cycles carboplatin-5FU; Strongly intensified CRT: 64Gy/5weeks+cisplatin (days 2, 16, 30) and 5 FU (days 1-5, 29-33) followed by 2 cycles adjuvant cisplatin-5FU.

Results: Median follow-up was 13.3 and 5.2years for GORTEC 96-01 and GORTEC 99-02, respectively. Five-year overall survival (OS) was 13.8%. No significant difference was observed between CRT versus VART in terms of OS (hazard ratio [HR]: 0.93, p=0.68), loco-regional progression (HR: 0.70, p=0.13), or distant progression (HR: 0.86, p=0.53). OS was worse for patients with T3-4 tumors versus early T stage (11.0% versus 25.7%, p=0.015). In multivariate analysis, the oropharyngeal subsite presented a higher risk of distant metastasis (as first event 46.5% vs 19.2%, p<0.001),). A significant interaction between treatment modalities and subsites has been observed concerning loco-regional and distant failures.

Conclusion: The outcome of N3 HNSCC was extremely poor despite treatment intensification and no difference between CRT and VART. Both distant metastases and loco-regional failures remain important treatment challenge.