Health utility scores (HUS) and health-related quality of life (HRQoL) in stage 4 lung cancer (S4LC) patients with brain metastases (BM).

Abstract

24 Background: Novel therapies have improved the survival of S4LC patients, particularly those with EGFR or ALK alterations. As BM are common among such patients, determining whether HUS appropriately capture BM-specific HRQoL is crucial in economic analyses. We evaluated the relationship between the FACT-Brain (Br) HRQoL, presence of BM, and HUS. Methods: This cross-sectional study of S4LC outpatients at a comprehensive cancer centre assessed FACT-Br and EQ-5D-3L-derived HUS. Correlational analyses, stratified by BM status, were performed between HUS and each of FACT-Br and its subscales: FACT-General (G), physical well-being (PWB), social well-being (SWB), emotional well-being (EWB), functional well-being (FWB), and brain cancer (BrC). Linear regression interaction models assessed whether BM modified the associations between FACT-Br or its subscales and HUS. Results: The 65 BM and 42 non-BM patients had similar demographics: median age (range) was 62 (30-83) years, 61% were female, 55% were Caucasian, and 54% were EGFR/ ALK+. Mean± standard error of the mean (SEM) values of HUS were similar between BM and non-BM groups (0.77±0.02 vs. 0.78±0.02; p=0.49). However, 40 BM patients with stable brain disease had higher HUS than the 14 with progressive disease (0.81 vs. 0.69; p=0.007). Mean±SEM values for FACT-Br, FACT-G, and BrC were 148±2.6, 79±1.5, and 69±1.3, respectively, with no differences between BM and non-BM groups. With the exception of SWB, FACT-Br and its subscales were each individually correlated with HUS (all p<0.001 unless specified), including between HUS and PWB (all patients: r=0.58; BM only: r=0.60; non-BM only: r=0.54), FACT-Br (all: r=0.55; BM: r=0.55; non-BM: r=0.54), FACT-G (all: r=0.51; BM: r=0.49; non-BM: r=0.55), and BrC (all: r=0.49; BM: r=0.51; non-BM: r=0.44, p=0.003). Having BM did not modify these relationships (each interaction, p>0.35). Conclusions: The FACT-Br HRQoL measures and the majority of its subcomponents moderately correlate with HUS but are not specific to patients with BM. Progression of CNS disease greatly alters HUS. EQ-5D-3L-derived HUS are a useful index of HRQoL in S4LC.