The Children and Adolescents Nasopharyngeal Carcinoma Survivor Study will investigate the long-term effects of nasopharyngeal carcinoma (NPC) and its associated therapies. A prospective and retrospective cohort study will be conducted through a multi-institutional collaboration. This project will study children and adolescents exposed to specific therapeutic modalities,including radiation,chemotherapy,and/or surgery,who are at increased risk of late-occurring adverse health outcomes. A group of sibling controls will be identified and data collected for comparison purposes.