The aim of phase 1 of this study is to develop a care need scale (CNS) for adolescents with cancer. The aim of phase 2 is to examine the mediating role of care needs between physical and psychosocial dysfunction and QoL, and to explore the recovery trajectory and its predictors regarding the care needs, physical and psychosocial factors, and the QoL of adolescents with cancer at the first, second, and third 3-month periods after initiating on-treatment and off-treatment. The aim of phase 3 is to examine the effectiveness of the computerized assessment with graphic outcome (CAGO) for fulfilling the care needs of adolescents with cancer, its acceptability for adolescents with cancer, and its usability for clinicians in pediatric oncology units.