Effect of delayed treatment on survival of patients with head and neck squamous cell cancer.

The impact of prolonged treatment delays on the survival outcomes of patients with head and neck squamous cell cancer (HNSCC) remains controversial. Patients were identified from the Surveillance, Epidemiology, and End Results (SEER) database. The association between diagnosis-to-treatment interval (DTI) and survival was assessed using Cox proportional hazards models and competing risk regression.4700 (6.1%) experienced treatment delays and 28,934 (37.8%) died due to cancer-specific causes. Treatment delays were associated with a worse overall survival (OS) and cancer-specific survival (CSS) of patients with cancer in the lip/oral cavity (OS: adjusted hazard ratio [aHR] = 1.16, 95% confidence interval [CI]: 1.08-1.24; CSS: aHR = 1.15, 95% CI 1.06-1.24), oropharynx (OS: aHR = 1.19, 95% CI 1.12-1.28; CSS: aHR = 1.19, 95% CI 1.10-1.28), and larynx (OS: aHR = 1.21, 95% CI 1.13-1.30; CSS: aHR = 1.21, 95% CI 1.10-1.33). However, treatment delay did not find significance on OS and CSS in patients with cancers of the hypopharynx, nasopharynx, nasal cavity and sinuses, or salivary glands at the time cutoff of 2 months for delayed treatment. Prolonged treatment delays were associated with an increased risk of mortality in patients with lip/oral cavity, oropharyngeal, and laryngeal cancers, and should be focused on in order to improve patient prognosis.