Health-Related Quality of Life in EORTC clinical trials — 30 years of progress from methodological developments to making a real impact on oncology practice

The impact of cancer on patients' lives can be measured using self-reported questionnaires, known as Health-Related Quality of Life (HRQOL) measures. HRQOL is defined as a multi-dimensional construct covering disease and treatment-related symptoms, physical, psychological, and social functioning.The EORTC Quality of Life Group (QLG) was created in 1984 with the mission to develop measures of HRQOL and to promote and coordinate clinical studies concerning the quality of life of cancer patients. The EORTC Quality of Life Department (QL Department) was founded in 1993 with the support of an EU grant to provide administrative, practical and scientific support to co-operative groups conducting clinical trials with HRQOL outcomes.We are proud to report significant scientific achievements that have made us international leaders in HRQOL research and have led to real changes to cancer patient treatments.We developed a modular system for HRQOL measurement consisting of the EORTC QLQ-C30, a core cancer quality of life questionnaire and supplementary questionnaire modules. The EORTC-QLQ-C30 has been one of the most widely used cancer questionnaires in randomized trials in oncology as demonstrated by systematic reviews. To date, the EORTC QLQ-C30 has been translated and linguistically validated into more than 60 languages.HRQOL outcome measures have been an integral part of EORTC clinical trials for the last 30 years. We present examples of significant, practice-changing clinical trials evaluating HRQOL in several cancer sites, such as brain tumors, breast and ovarian cancers, and malignant melanoma. In a series of systematic reviews, we examined the quality of reporting HRQOL in international cancer clinical trials, and the impact of the results on oncology practice that led to a recommendation to improve CONSORT (Consolidated Standards of Reporting Trials) with regard to reporting of HRQOL.The QLG is an international leader in methodological research in the measurement of HRQOL in oncology and pursues research in several key areas, such as cross-cultural differences between populations in HRQOL assessment, Computer-Adaptive Testing, electronic administration of EORTC QLQ-C30, and summary scores for EORTC QLQ-C30.In summary, the QLG and QL Department have been international leaders in the field. Our questionnaires have brought HRQOL assessment to the fore in many international trials that have changed oncology practice and brought the patient's perspective into cancer research.