Cancer rehabilitation and supportive care should be evidence-based and tailored to the individual patient. To contribute to this goal, the POLARIS has three aims:

To set up an international infrastructure and data-base comprising high quality randomized controlled trials to conduct an individual patient data meta-analysis evaluating the effect of exercise and psychosocial interventions on the quality of life of patients with cancer.

To evaluate which sociodemographic, clinical and personal characteristics and intervention type and circumstances moderate the effect of exercise and psychosocial interventions on quality of life of cancer patients, and whether the intervention effect on quality of life is mediated by fatigue, physical fitness and function and psychosocial function  (Figure 1). 

To build and validate a clinical prediction model identifying the most relevant predictors of intervention success, and to develop a clinical decision rule for tailored and evidence-based decision making with respect to cancer rehabilitation and supportive care to optimize quality of life.

 Figure 1: Hypothetical model of the intervention effect on quality of life