In my doctoral research I investigated the quality of life of cancer survivors who were diagnosed with cancer 5-15 years ago. We wanted to know how much influence cancer still has on people who had cancer long ago. In 2007, this resulted in a dissertation, which showed that cancer survivors generally thought their quality of life was good, but that they often still suffered from side effects from the disease or its treatment. I continued with this research and it now has a broader scope. We currently include patients from diagnosis onwards and follow them for years. In addition to quality of life, we also investigate broader concepts such as depression and fatigue. Besides questionnaires, we now also collect data by means of blood samples, Actigraphs, Fitbits, online food diaries and scales. We are also investigating this in patients with rare tumors, such as thyroid cancer.