Influence of Grading on Management and Outcome in Mucoepidermoid Carcinoma of the Parotid—A Multi‐institutional Analysis
Stefan Grasl, Stefan Janik, Muhammad Faisal, M. Grasl, Johannes Pammer, Ilan Weinreb, Gregor Fischer, John Kim, Ali Hosni, John R. de Almeida, David P. Goldstein, Boban M. Erovic
Abstract
OBJECTIVE: To evaluate clinical outcome of low (G1), intermediate (G2), and high-(G3) grade mucoepidermoid carcinomas (MEC) of the parotid gland. STUDY DESIGN: Retrospective chart review including 212 patients. Clinicopathological data was statistically analyzed regarding grading, overall survival (OS), disease-free survival (DFS) and disease-specific survival (DSS). RESULTS: 105 (49.5%) G1, 73 (34.5%) G2, and 34 (16%) G3 MEC were included and 56 (26.4%) patients presented with neck node metastases. The risk of occult nodal metastases was significantly associated with grading and increased from 9.2% in G1 to 26.7% and 27.8% in G2 and G3 tumors, respectively (p = 0.008). Elective periparotid and cervical lymph node dissection was performed in 170 (80.2%) and 70 (33%) patients, respectively. All patients with positive periparotid nodes when subjected to an additional neck dissection had associated cervical neck node involvement (p < 0.001). Grading was an independent significant prognostic factor for OS (HR 4.05; 95%CI: 1.15-14.35; p = 0.030) and DSS (HR 17.35; 95%CI: 1.10-273.53; p = 0.043). In a subgroup analysis, elective neck dissection (END) was also significantly associated with a better DFS (p = 0.041) in neck node-negative G1 MECs. CONCLUSION: The risk of occult nodal metastasis in intermediate-grade MEC is as high as in high-grade MEC and that END in G1 tumors is associated with a prolonged DFS. Additionally, periparotid node involvement seems to be a predictor for positive neck node involvement. This study presents some preliminary data to consider END in clinically neck node negative patients with parotid MEC; however, larger series are needed. LEVEL OF EVIDENCE: 3 Laryngoscope, 133:124-132, 2023.