Clustering of EORTC QLQ-C30 health-related quality of life scales across several cancer types: Validation study.

INTRODUCTION: The European Organisation for Research and Treatment of Cancer Quality of Life Core Questionnaire (EORTC QLQ-C30) measures 15 health-related quality of life (HRQoL) scales relevant to the disease and treatment of patients with cancer. A study by Martinelli (2011) demonstrated that these scales could be grouped into three main clusters: physical, psychological and gastrointestinal. This study aims to validate Martinelli's findings in an independent dataset and evaluate whether these clusters are consistent across cancer types and patient characteristics. METHODS: Pre-defined criteria for successful validation were three main clusters should emerge with a minimum R-squared value of 0.51 using pooled baseline-data. A cluster analysis was performed on the 15 QLQ-C30 HRQoL-scales in the overall dataset, as well as by cancer type and selected patient characteristics to examine the robustness of the results. RESULTS: The dataset consisted of 20,066 patients pooled across 17 cancer types. Overall, three main clusters were identified (R2 = 0.61); physical-cluster included role-functioning, physical-functioning, social-functioning, fatigue, pain, and global-health status; psychological-cluster included emotional-functioning, cognitive-functioning, and insomnia; gastro-intestinal-cluster included nausea/vomiting and appetite loss. The results were consistent across different levels of disease severity, socio-demographic and clinical characteristics with minor variations by cancer type. Global-health status was found to be strongly linked to the scales included in the physical-functioning-related cluster. CONCLUSION: This study successfully validated prior findings by Martinelli (2011): the QLQ-C30 scales are interrelated and can be grouped into three main clusters. Knowing how these multidimensional HRQoL scales are related to each other can help clinicians and patients with cancer in managing symptom burden, guide policymakers in defining social-support plans and inform selection of HRQoL scales in future clinical trials.

Reference values for the EORTC QLQ-C30 in patients with advanced stage Hodgkin lymphoma and in Hodgkin lymphoma survivors.

OBJECTIVES: To provide reference values for the European Organisation for Treatment and Research of Cancer (EORTC) Quality of Life Questionnaire (QLQ-C30) in advanced-stage Hodgkin lymphoma (HL) patients and 5-year HL survivors. The QLQ-C30 is the most widely used cancer-specific questionnaire to assess Health-Related Quality of Life (HRQoL). METHODS: The EORTC database was searched to identify HL RCTs in which patients' and survivors' HRQoL was assessed by the QLQ-C30. HRQoL mean scores were calculated and stratified by age and gender. Minimal important differences were used to assess the clinical relevance of the findings. Data from one RCT with HRQoL scores available at baseline (n = 343) and four RCTs with HRQoL scores available at follow-up (n = 1665) were analyzed. RESULTS: Patients reported worse HRQoL scores than survivors across most functioning scales and symptoms' scales. These scores varied as a function of gender but not age. Survivors' HRQoL reports were comparable to the ones of the general population. CONCLUSIONS: These values provide an assessment framework for the comparison and interpretation of QLQ-C30 scores in advanced-stage HL. Our findings suggest that although HL patients' HRQoL scores are worse than the general population, HRQoL scores may normalize over long-term survival.

Reference values for the EORTC QLQ-C30 in early and metastatic breast cancer.

BACKGROUND: Considering the worldwide incidence of breast cancer (BC) and the importance of health-related quality of life (HRQoL) assessment, there is a growing need to have accurate and up-to-date reference values (RVs). RVs are useful for the design of randomised controlled trials (RCTs) and as benchmarks for comparison of cancer RCTs and health care interventions. This study aimed to provide RVs for the QLQ-C30 in early BC (EBC) and metastatic BC (MBC). General patterns of main results from the EORTC dataset (main dataset) were compared with the PDS dataset (comparison dataset) to see whether they would be consistent across pre-defined covariates. METHODS: European Organization for Research and Treatment of Cancer (EORTC) (main dataset) and Project Data Sphere (PDS) (comparison dataset) were searched to identify BC RCTs where baseline HRQoL (before treatment) was assessed with the QLQ-C30. RVs were calculated and stratified by disease stage, age, and when available, performance status (PS), comorbidity and region. RVs were reported using descriptive statistics. RESULTS: Data from three EORTC (n = 4115) and three PDS RCTs (n = 1406) were included in the analysis. While EBC patients presented better HRQoL with high baseline functioning scores and low prevalence of symptoms, MBC patients reported worse HRQoL with lower functioning scores and more prevalence of symptoms. In MBC, poor PS and presence of comorbidities reflected worse baseline HRQoL. No consistent differences were found for age and countries. CONCLUSION: These up-to-date RVs for the EORTC QLQ-C30 in BC show differences in HRQoL scores between stages, PS, and comorbidities. These findings, supported by an independent dataset, will help the clinical interpretation of scores for BCpatients.