A risk factor for newly diagnosed secondary cancer in patients with early-stage laryngeal, oropharyngeal, or hypopharyngeal cancer: sub-analysis of a prospective observation study.

Among patients with early-stage laryngeal, oropharyngeal, and hypopharyngeal squamous cell carcinoma, who were initially treated with TOS, hypopharyngeal cancer patients had a higher risk of newly diagnosed secondary cancers as observed during the follow-up period.