Primary Salivary Type Lung Cancers in the National Cancer Database

Background Primary salivary type lung cancers such as adenoid cystic carcinoma (ACC) and mucoepidermoid carcinoma (MEC) are uncommon primary lung tumors that, given their rarity, remain incompletely understood. This study aimed to characterize the management and outcomes associated with these less common pulmonary malignancies. Methods Patients in the National Cancer Database diagnosed with primary lung and bronchial (not tracheal) MEC and ACC between 2004 and 2014 were identified. Adjusted mortality risk of surgically managed patients was evaluated in multivariable Cox proportional hazards regression models. Results In all, 699 MEC patients and 424 ACC patients were identified. The MEC tumors were smaller (mean size 3.1 cm versus 3.8 cm, p p p p  = 0.01), tumor size greater than 4 cm (HR 6.7, 95% CI: 2.0 to 22.0, p  = 0.01), and wedge resection (HR 3.7, 95% CI: 1.1 to 12.0, p  = 0.03) to be associated with increased risk of death. For ACC patients, incomplete tumor resection, R1 versus R0 (HR 4.0, 95% CI: 1.5 to 10.6, p  = 0.006), and distant metastases (HR 12.6, 95% CI: 2.5 to 64.4, p  = 0.002) were associated with increased mortality. Conclusions Pulmonary MEC and ACC appear to have distinct physical and oncologic attributes in the National Cancer Database. Although the overall prognosis appears to be favorable, there are subsets of primary salivary type lung cancers with increased mortality risk, and efforts should be made to completely resect these tumors.