The research of Geertruida de Bock is about the early detection of cancer and improvement of outcomes after cancer treatment. To evaluate this in a systematic way, she set up an UMCG’s oncology databiobank OncoLifeS with quality of life as a main outcome. To assess and optimize screening strategies, she works on defining which populations are at risk of cancer and negative outcomes. She does not only consider benefits of screening and treatment, but also the negative effects of over-diagnosis, tumor-induction, false-positive results, and side-effects. Systematic literature reviews, analysis of cohorts and modelling are the most important methods she uses.