A randomized phase III trial for alleviating radiation-induced xerostomia with chewing gum

Xerostomia is frequently reported after radiotherapy (RT) for head and neck cancer (HNC). The aim of this study was to reduce symptoms of radiation-induced xerostomia in HNC survivors, in which the experimental arm used chewing gum for a month. Primary endpoint was changes in scoring of dry mouth as defined by EORTC QLQ-H&N35 between arms.

Participants with any grade of physician-assessed xerostomia, ≥ six month after RT, disease-free and able to chew gum were, for a month, randomized (2:1) to: (Arm A) daily chewing gum or (Arm B) standard care. Xerostomia-related QOL was assessed using EORTC QLQ-H&N35 and GRIX questionnaires along with measurement of salivary flow and viscosity at inclusion and after one month. The study was registered on ClinicalTrials.gov (NCT03302676).

Ninety-one participants were eligible for analysis (Arm A, n = 55; Arm B, n = 36). Comparing categorized scores for symptoms between arms, reduction of dry mouth was significantly higher for Arm A than Arm B (p = 0.05). A reduction in dry mouth scores was observed for xerostomia assessed by EORTC QLQ-H&N35 (question 41) for both arms. Salivary flow increased and viscosity decreased upon five minutes of stimulation within both arms (p < 0.001, respectively), however no significantly difference was observed between arms.

Categorized scores found reduction of dry mouth to be significantly higher in Arm A than Arm B, but no difference was seen for salivary flow rate and viscosity.