Relevance of this study: Fatigue long after treatment for cancer is a frequently occurring problem, which has important consequences for quality of life in these patients. Identification of characteristic (neuro)physiological factors of fatigue in disease-free cancer patients may not only serve a theoretical understanding of this invalidating condition, but may also provide an objective biological marker that could support the diagnosis and follow-up of treatment. The identification of (neuro)physiological factors which play a role in fatigue after cancer may aid in the early recognition of patients who are at risk for developing fatigue and may lead to early intervention and/or different treatment strategies.