Analysis of the Prognostic Factors for Distant Metastasis after Induction Chemotherapy Followed by Concurrent Chemoradiotherapy for Head and Neck Cancer

PURPOSE: The aim of this study is to identify the prognostic factors of distant metastasis (DM) after induction chemotherapy (IC) followed by concurrent chemoradiotherapy (CRT) for locoregionally advanced head and neck cancer (HNC). MATERIALS AND METHODS: A total of 321 patients with HNC who underwent IC followed by CRT treated between January 2005 and December 2010 were analyzed retrospectively. IC consisted of three courses of docetaxel (70 mg/m(2)) and cisplatin (75 mg/m(2)) every three weeks, followed by radiotherapy of 66-70 Gy/2 Gy per fraction/5 fractions per week concurrent with weekly cisplatin (40 mg/m(2)). Tumor/nodal stage, primary site, tumor differentiation, lower neck node involvement (level IV, VB, and supraclavicular regions), number of concurrent chemotherapy cycles, overall duration of radiotherapy, and response to IC were assessed as potential prognostic factors influencing DM and survival outcome. RESULTS: The five-year loco-regional recurrence and DM rates were 23.6% and 18.2%. N stage, overall duration of radiotherapy, lower neck node involvement, and response to IC were significant factors for DM. With a median follow-up period of 52 months (range, 4 to 83 months), the 5-year progression-free, DM-free, and overall survival rates were 41.2%, 50.7%, and 55.1%, respectively. Lower neck node involvement (p=0.008) and poor response to IC (p < 0.001) showed an association with significantly inferior DM-free survival. CONCLUSION: Even with the addition of IC, the DM rate and survival outcome were poor when metastatic lower neck lymph nodes were present or when patients failed to respond after receiving IC.