Abstract
METHODS
Data were obtained from 46 clinical trials across three cancer research networks conducted between 1996 and 2013 that assessed HRQoL using the EORTC QLQ-C30. A stratified Cox proportional hazards model was employed to assess the prognostic significance of baseline QLQ-C30 scale scores on overall survival, adjusting for socio-demographic and clinical variables. Stepwise model selection was done at 5% significance level. Model stability and prognostic accuracy were evaluated via bootstrapping and the C index respectively.
BACKGROUND
A pooled data analysis by Quinten et al. (2009) found three European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30) health-related quality of life (HRQoL) scales to be prognostic for survival: physical functioning, pain and appetite loss. This study aims to replicate these findings in an independent data set comprising a broader cancer population.
FINDINGS
Data from 16,210 patients reporting HRQoL at baseline, spanning 17 cancer types, was used. The stratified multivariable model confirmed that better physical functioning (hazard ratio [HR], 0.94; 95% confidence interval [CI], 0.93-0.96), lower pain (HR, 1.02; 95% CI, 1.01-1.03), and appetite loss (HR, 1.04; 95% CI, 1.03-1.05) were significantly associated with survival. Additionally, global health status/QoL, dyspnoea, emotional and cognitive functioning were found to be prognostic for survival. This final model, encompassing sociodemographic, clinical, and HRQoL variables, achieved a corrected C index of 0.74, marking a 48% enhancement in discriminatory ability. Bootstrap evaluation indicated no major instability issues.
FUNDING
EORTC Quality of Life Group.
INTERPRETATION
These results support previous findings that baseline physical functioning, pain, and appetite loss scores, along with four other scales from the EORTC QLQ-C30, predict survival in cancer patients.