Long-term outcomes of induction chemotherapy followed by chemoradiotherapy vs chemoradiotherapy alone as treatment of unresectable head and neck cancer: follow-up of the Spanish Head and Neck Cancer Group (TTCC) 2503 Trial.

Background Our previous phase-3 study (TTCC 2503) failed to show overall survival advantage of 2 induction chemotherapy (IC) regimens followed by standard concurrent chemoradiotherapy (CRT) over CRT alone in patients with unresectable locally advanced head and neck squamous-cell carcinoma (LAHNSCC). This study described the long-term survival of those patients. Materials and methods Long-term follow-up study of patients with untreated LAHNSCC assigned to IC (three cycles), with either docetaxel, cisplatin and 5-fluorouracil (TPF arm) or cisplatin and 5-fluorouracil (PF arm), followed by CRT, or CRT alone, included in the previous TTCC 2503 trial. Results In the intention-to-treat population (n = 439), the median OS times were 25.4 (95% CI, 16.8-34.4), 26.2 (95% CI, 18.2-36.6) and 25.4 months (95% CI, 17.4-36.0) in the TPF-CRT, PF-CRT and CRT arms, respectively (log-rank p = 0.51). In the per-protocol population (n = 355), patients with larynx-hypopharynx primary tumors treated with IC (TPF or PF) followed by CRT had a longer median PFS than those who received CRT alone. Moreover, patients with ECOG 0 treated with IC (TPF or PF) followed by CRT had a better TTF than those with CRT alone. There were no statistically significant differences in terms of OS, PFS or TTF, according to the tumor load or affected nodes. Conclusion After a long follow-up, the TTCC 2503 trial failed to show the benefit of IC-CRT in unresectable LAHNSCC regarding the primary end point. However, fit patients with ECOG 0 and primary larynx-hypopharyngeal tumors may benefit from the use of IC if administered by an experienced team. ClinicalTrials.gov identifier NCT00261703.