Introduction: Salivary gland cancer (SGC) is a rare malignant tumor arising from the salivary glands, with a variety of clinical and biological behaviors different from head and neck cancer (HNC). Because of the rarity of SGC, there are limited data on pre-treatment quality of life (QoL). Therefore, we evaluated the pre-treatment QoL in SGC patients by stage and compared it with that of HNC patients.

Methods: From a prospective registry of HNC patients (2016-2020), we selected 225 patients with SGC, and 912 patients with oral cavity (OC) and oropharyngeal cancer (OPC) who were diagnosed in the same period as the HNC control group. The European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire Core 30 (QLQ-C30) and HNC-Specific Module (H&N35) were used to assess QoL.

Results: SGC patients had a statistically better baseline QoL (69.8 vs. 64.0), emotional (82.1 vs. 78.8), cognitive (92.0 vs. 88.7), and social function (86.3 vs. 80.5), and fewer symptoms than HNC patients. The estimated average QoL differences between SGC patient diagnosed at stages I and IV was -12.9. Especially, advanced-stage of tumors was associated with much lower role functioning and emotional functioning scores in SGC patients, compared to those in HNC patients, among females and of younger age.

Discussion: Although the overall QoL score was higher in SGC patients than in HNC patients, specific domains were significantly affected in SGC patients according to the tumor stage. Females and those of younger age were more affected by severity of disease in SGC.

Study registration: ClinicalTrials.gov Identifier NCT02546895.