Impact of smoking cessation on clinical outcomes in patients with head and neck squamous cell carcinoma receiving curative chemoradiotherapy: A prospective study.

BACKGROUND: We hypothesized that patients with head and neck squamous cell carcinoma (HNSCC) with smoking cessation during curative chemoradiotherapy (CRT) had fewer complications and lower tumor progression risks. METHODS: Sixty-three patients with nonmetastatic HNSCC who were smokers at diagnosis (carbon monoxide [CO] breath concentrations ≥3 ppm) and underwent curative CRT were prospectively enrolled. Successful smoking cessation throughout CRT was confirmed by CO breath concentrations <3 ppm at CRT completion. RESULTS: Forty-one patients (65%) successfully discontinued smoking throughout CRT. With a median 33-month follow-up, patients with successful smoking cessation during CRT had significantly fewer, greater, and lower probabilities of grade ≥3 acute toxicities (P = .01), progression-free survival (P = .03), and permanent gastrostomy or tracheostomy (P = .04), respectively, than those continuing smoking throughout CRT. In multivariate analysis, successful smoking cessation during CRT significantly reduced tumor progression risks (hazard ratio: 0.4, P = .05). CONCLUSION: Smoking cessation during curative CRT reduced treatment-related toxicities and tumor progression risks in patients with HNSCC.