Quality of life and chronotherapy

The importance of evaluating patient's quality of life (QoL) in clinical practice and research is recognized clearly in oncology. In the advanced phase of disease such an evaluation represents an endpoint as important as survival. Quality of life is both a subjective and multidimensional concept evaluated mainly by validated questionnaires. In colorectal trials involving advanced stage disease the effects of different chemotherapy treatments on QoL were evaluated. Almost all the studies found no deterioration in QoL during chemotherapy. The European Organization for the Research and Treatment of Cancer (EORTC) Chronotherapy Study Group utilized three different approaches to assess QoL. The first centered on the stability of QoL during a 6mon treatment period in patients undergoing chronotherapy. The second centered on research of the biological and clinical determinants of QoL involving features of the circadian activity rhythm and patient survival and the relationship between QoL and patient performance status, response to therapy, and psychosocial variables as well as drug-induced toxicity. The third centered on the clinical effectiveness of psychological intervention on patients undergoing chronotherapy to improve psychosocial status during treatment. This papers reviews the results of EORTC Chronotherapy Group studies on QoL.