Effectiveness of planned surveillance for detecting second primary head and neck cancers after endoscopic resection of esophageal squamous cell carcinoma

Background: Second primary head and neck cancers after endoscopic resection of esophageal squamous cell carcinoma adversely affect patients' outcomes and the quality of life; however, an adequate surveillance schedule remains unclear. Methods: We analyzed 330 patients with early esophageal squamous cell carcinoma who underwent endoscopic resection and were registered in the multicenter cohort study to evaluate adequate surveillance for detection of second primary head and neck cancers. Gastrointestinal endoscopists examined the head and neck regions after 3-6 months of endoscopic resection for esophageal squamous cell carcinoma and subsequently every 6 months. An otolaryngologist also examined the head and neck regions at the time of endoscopic resection for esophageal squamous cell carcinoma and at 12 months intervals thereafter. Results: During the median follow-up period of 49.4 months (1.3-81.2 months), 33 second primary head and neck cancers were newly detected in 20 patients (6%). The tumor site was as follows: 22 lesions in the hypopharynx, eight lesions in the oropharynx, two lesions in larynx and one lesion in the oral cavity. The 2-year cumulative incidence rate of second primary head and neck cancers was 3.7%. Among them, 17 patients with 29 lesions were treated by transoral surgery. One patient with two synchronous lesions was treated by radiotherapy. Two lesions in two patients were not detected after biopsy. All patients were cured with preserved laryngeal function. Conclusions: Surveillance by gastrointestinal endoscopy every 6 months and surveillance by an otolaryngologist every 12 months could detect second primary head and neck cancers at an early stage, thereby facilitating minimally invasive treatment.