How health-related quality of life assessment should be used in advanced colorectal cancer clinical trials

Traditionally, the efficacy of cancer treatment in patients with advance or metastatic disease in clinical studies has been studied using overall survival and more recently tumor-based end points such as progression-free survival, measurements of response to treatment. However, these seem not to be the relevant clinical end points in current situation if such end points were no validated as surrogate of overall survival to demonstrate the clinical efficacy. Appropriate, meaningful, primary patient-oriented and patient-reported end points that adequately measure the effects of new therapeutic interventions are then crucial for the advancement of clinical research in metastatic colorectal cancer to complement the results of tumor-based end points. Healthrelated quality of life (HRQoL) is effectively an evaluation of quality of life and its relationship with health over time. HRQoL includes the patient report at least of the way a disease or its treatment affects its physical, emotional and social well-being. Over the past few years, several phase III trials in a variety of solid cancers have assessed the incremental value of HRQoL in addition to the traditional end points of tumor response and survival results. HRQoL could provide not only complementary clinical data to the primary outcomes, but also more precise predictive and prognostic value. This end point is useful for both clinicians and patients in order to achieve the dogma of precision medicine. The present article examines the use of HRQoL in phase III metastatic colorectal cancer clinical trials, outlines the importance of HRQoL assessment methods, analysis, and results presentation. Moreover, it discusses the relevance of including HRQoL as a primary/co-primary end point to support the progression-free survival results and to assess efficacy of treatment in the advanced disease setting.