Diagnosis and treatment of early esophageal carcinoma and second primary tumors in the upper aerodigestive tract

This thesis aims to provide insights in the incidence and risk of second and multiple primary tumors (MPTs) in the upper aerodigestive tract (UADT) in patients with esophageal squamous cell carcinoma (ESCC) and in patients with head and neck squamous cell carcinoma (HNSCC). The second aim of this thesis is to investigate whether screening for these MPTs should be recommended. The third aim of this thesis is to optimize clinical staging and endoscopic resection (ER) of early esophageal cancer (EC) and to develop a prediction model that estimates the risk of lymph node metastases (LNM) in individual patients with submucosal (pT1b) esophageal adenocarcinoma (EAC)