Prediction of the depth of invasion in superficial pharyngeal cancer: Microvessel morphological evaluation with narrowband imaging

Abstract Background Magnifying endoscopy with narrowband imaging (ME‐NBI) is useful in predicting the invasion depth by examining the microvascular status of tumor surfaces. This retrospective study aimed to determine its efficacy in pharyngeal cancer. Methods Between April 2016 and March 2018, 59 lesions from 46 patients who underwent transoral resection were retrospectively analyzed. Using ME‐NBI, microvascular status was classified into B1, B2, or B3, based on the classification of the Japan Esophageal Society. Results A significant correlation was observed between microvascular status and invasion depth ( P = .011). Mean thickness of lesions with B1, B2, and B3 vessels were 563, 1364, and 2825 μm, respectively ( P = .006). In previously treated lesions, a significant correlation was observed between microvascular status and invasion depth ( P = .012). Conclusions ME‐NBI is useful in predicting the invasion depth and thickness of pharyngeal tumors, even in patients with previously treated lesions.