Predictors of cervical lymph node involvement in patients with pharyngeal carcinoma undergoing endoscopic mucosal resection

Abstract Objective Although detection of pharyngeal carcinoma remaining in the epithelium or subepithelial tissue layer has been difficult by routine examinations, recent advances in endoscopic technology have enabled us to detect these lesions. These patients can receive endoscopic mucosal resection (EMR) and generally have a good prognosis, but some patients have nodal involvement. The purpose was to investigate predictors of nodal involvement in patients with pharyngeal carcinoma undergoing EMR at our hospital. Study design Outcomes research. Methods Lymph node involvement, endoscopic morphology, and tumor thickness were investigated in 152 patients treated between 2001 and 2009. Results Pathological examination revealed carcinoma in situ (CIS) for 77 patients and subepithelial invasion (SEPI) for 75 patients. There were no patients with muscular invasion. Nodal involvement was found in none of CIS but in 7 of 75 patients (9.3%) with SEPI. In patients with SEPI, the mean tumor thickness was significantly higher in patients with lymph node involvement (1311.4 ± 300.0 μm) than those without involvement (692.6 ± 495.7 μm) ( p = 0.002). Significant risk factors for nodal involvement included the tumor thickness over 1000 μm ( p < 0.001) and the presence of venous or lymphatic invasion ( p < 0.05). Based on analysis in relation to sensitivity and specificity, the tumor thickness over 1000 μm may serve as the most predictive factor for nodal involvement. Conclusion Tumor thickness can be a simple predictor for nodal involvement in cases of SEPI. Careful follow-up including neck palpation and annual imaging diagnostics such as computed tomography or ultrasonography are recommended for these patients.