Association of quality of life with mortality in patients with adenoid cystic carcinoma using an internationally-validated QoL questionnaire (EQ-5D-5L)

BACKGROUND/OBJECTIVES: An evaluation of quality of life (QoL) is increasingly required for approval and reimbursement of new drug therapies. To support the evaluation of the impact of new drug therapies on QoL in single-arm studies in adenoid cystic carcinoma (ACC), we sought to determine the QoL baseline in a cohort of patients with ACC during routine follow up visits and to assess for associations with clinical or prognostic factors. METHODS: An internationally-validated QoL questionnaire (EQ-5D-5L) was completed by patients with ACC referred to an experimental medicine centre. EQ-5D value scores (EQV) were calculated from each questionnaire using the EuroQol England value set. A Cox proportional hazards model was built with EQV as a time-dependent variable. Non-linear mixed effects modelling (NLME) was used to test the relationship between EQV and predictors (time, NOTCH1 status, age at diagnosis, sex, local and/or metastatic recurrence, and primary site of disease). RESULTS: Between 2019 and 2023, 563 questionnaires were completed by 161 patients with ACC. Median EQV was 0.81 (range -0.22 to 1.0) and mean EQV was 0.79. A decrease in EQV from 1 to 0 was associated with an eightfold increase in risk of death in the total population (HR = 0.118, 95 % CI 0.057 to 0.244, p=<0.001). No predictor had a significant impact on EQV in NLME except time (p=<0.001). CONCLUSIONS: For patients with ACC, a worse QoL as measured by EQ-5D-5L was associated with a significantly increased risk of death. It remains unclear if poorer QoL has a causal relationship with mortality.