Health-related quality of life is often an endpoint in oncology clinical trials. The European Organization for Research and Treatment of Cancer (EORTC) developed the cancer-specific quality of life questionnaire (QLQ-C30), which includes five functions, nine symptoms, and a global health status. These questionnaires are completed by the patients themselves throughout the process of care. The recommended approaches for processing EORTC QLQ-C30 data are usually descriptive and graphic.