The ACTION (Asean CosTs In ONcology) Study will be one of the largest observational studies of the burden of cancer ever conducted in Asia. The study will involve 10,000 newly diagnosed patients with cancer and will be carried out across eight low- and middle income countries within the ASEAN region (Indonesia, Thailand, Malaysia, Cambodia, Myanmar, Viet Nam, Laos and the Philippines). Patients will be interviewed three times over 12 months to assess their health, use of health care services, out of pocket costs related to their illness, social and quality of life issues. The project is a collaboration between the George Institute for Global Health, the ASEAN Foundation and Roche. The aim of the study is to assess the health and socioeconomic impact of cancer on patients in ASEAN communities, and the factors that may impact on these outcomes.