Prognostic factors and occult nodal disease in mucoepidermoid carcinoma of the oral cavity and oropharynx: An analysis of the National Cancer Database

Abstract

Objectives: Mucoepidermoid carcinoma (MEC) is an uncommon malignancy that most commonly occurs in the parotid gland followed by the minor salivary glands of the upper aerodigestive tract, most notably in the oral cavity (OC) and oropharynx (OP). Because of its rarity, few studies have been performed that are specific to MEC within the OC and OP. The objective of this study is to describe the tumor characteristics and prognostic features for MEC of the OC and OP.

Materials and methods: The National Cancer Database (NCDB) was used for this study. The primary outcome measure was 5-year overall survival (OS). The secondary outcome measure was occult nodal disease. Fischer's exact tests, chi-square tests, log-rank tests and Cox proportional hazards analyses were performed.

Results: We identified 3005 patients with MEC of the OC/OP. The 5-year overall survival for MEC of the OC and OP was 87%. Increasing age, male sex, Charlson/Deyo comorbidity score of 2+, clinical T3-4 tumors, nodal+disease, high grade tumors and positive margins were independently associated with decreased 5-year OS. Occult nodal disease occurred in 14.1% and 17.3% of high grade and clinical T3-T4 tumors respectively.

Conclusion: MEC of the OC/OP has an excellent survival as the majority of these patients have low/intermediate grade and early stage disease. Negative prognosticators include increasing age, male sex, Charlson/Deyo comorbidity score of 2+, clinical T3-4 tumors, nodal+ disease, high grade tumors and positive margins. Our findings justify strong consideration of prophylactic neck dissection for high grade and clinical T3-4 tumors.

Keywords: Minor salivary glands; Mucoepidermoid carcinoma; National cancer database; Occult nodal disease; Oral cavity; Oropharynx; Overall survival.