Esophageal screening
Since 2016, patients with head and neck cancer in our hospital have received routine IEE screening of the esophagus. Patients who were newly diagnosed with head and neck cancer received IEE screening before treatment of the index primary tumor. For patients with a history of head and neck cancer, IEE was also arranged annually during their follow-up outpatient visits. IEE was performed by three experienced endoscopists for diagnosis and treatment at the endoscopy center of our hospital using high-resolution zoom endoscopy and narrow-band imaging using the Evis Lucera CV-290 Endoscopy Processer System (GIF-H260Z or GIF-H290Z; Olympus Medical System Corp, Tokyo, Japan). A soft black hood (MAJ-1989, Olympus Medical System Corp, Tokyo, Japan) was attached to the tip of the endoscope to obtain an optimal image of up to 80x magnification. For patients with trismus, a 5.5-mm diameter endoscope (XP-260N or XP-290N, Olympus Medical System Corp, Tokyo, Japan; Evis Lucera CLV-290) was used for examination. For detection of any suspicious mucosal lesions in the upper gastrointestinal tract, white-light endoscopy (WLE) and narrow-band imaging with magnification (NBI-M) were used for initial endoscopic evaluation. Then Lugol chromoendoscopy was performed by steadily spraying approximately 10–20 ml of iodine staining (Lugol’s solution) over the entire esophagus via dye-spraying catheter (PW-5L-1, Olympus Medical System Corp, Tokyo, Japan). Endoscopic biopsies were performed on all suspected ESCNs as follows: (1) hyperemic changes, ulcerations, uneven, or nodular mucosa under WLE (Fig 1-1), (2) brownish discoloration of mucosa with abnormal intraepithelial capillary loop pattern according to Japanese Esophageal Society (JES) classification Type B1-B3 under NBI-M (Fig 1-2),11 (3) demarcated Lugol-voiding lesions (LVLs) of diameter >0.5cm (Fig 1-3), (4) LVLs with pink-color sign (Fig 1-4).
The biopsied tissues were sent for pathological studies. The ESCNs in this study included high-grade dysplasia, carcinoma in situ, and SCC. The 7th edition of the American Joint Committee on Cancer were used for tumor staging.12
Second primary ESCN was defined based on the criteria established by Warren and Gate in 1932 as follows: (1) both tumors are malignant on histological examination, (2) the tumor must be anatomically separated by normal mucosa, and (3) the possibility that one tumor represents metastasis from the other must be excluded.13