Millions of cancer patients will continue to be diagnosed each year for the foreseeable future. They all need to access optimal health care. Population-based cancer survival is a key measure of the overall effectiveness of health systems in managing cancer. Survival varies very widely around the world. Global surveillance of cancer survival is required, because unless these largely avoidable inequalities are measured, and reported regularly, nothing will be done to ameliorate them.
The burden of cancer In 2008, an estimated 12.7 million patients were diagnosed with cancer, and 7.6 million cancer deaths occurred. More than half (56%) of the cancer diagnoses and 64% of the deaths were among people living in low- and middle-income countries (LMIC)1. The annual number of newly diagnosed cancer patients will rise substantially by 2030 because of ageing of the world’s population, growth in population size and for many persons, an increase in their risk of developing cancer at each age (age-specific risks). All three factors will affect poorer countries more. Prevention remains preferable to cure, especially for such a lethal constellation of diseases. The need for long-term investment in primary prevention to reduce age-specific cancer risks for future populations remains equally inescapable. However, since we cannot expect the manufacturers and purveyors of tobacco to fall on their swords any time soon, the responsibility for primary prevention falls to politicians and other leaders of society with the courage, the selflessness and the long-term vision to develop and implement policies for cancer prevention that will probably not bear fruit during their political life-time. The Framework Convention for Tobacco Control (http://www.who.int/fctc/about/en/index.html) offers a good starting point. Long-term reductions in tobacco consumption have led to long-term declines in lung cancer incidence in a number of countries. Where we do know the cause(s) of cancer, the latency between causative exposure(s) and clinical disease is often measured in decades, not years, and for around half of all cancers, we do not know the cause, so primary prevention is not yet possible. Thus, even if every cancer prevention measure that we know to be effective today were applied to every person, worldwide, tomorrow, and even if those measures were instantly and completely effective, in every person overnight – for example, abolishing the 20-fold lung cancer risk in heavy smokers – millions of people would continue to be diagnosed with cancer each and every year for the foreseeable future. Unfortunately, cancer prevention is not even close to being that prompt, that effective, or that widespread: the Framework Convention for Tobacco Control was adopted by the World Health Assembly in 2003, more than 50 years after the discovery that tobacco smoking causes cancer. The millions of cancer patients diagnosed every year will continue to need ready access to optimal treatment to optimize their chances of survival, wherever they live. The provision of adequate health care is a responsibility for governments everywhere. The survival of all cancer patients diagnosed with cancer in a given population is one of the most important measures we have of the overall effectiveness of the health care system for the treatment and management of cancer. Unsurprisingly, there is huge global inequity in access to cancer care2. The first CONCORD study showed for the first time that global disparities in cancer survival were equally wide3. CONCORD-2 will bring those estimates up to date. It will initiate global surveillance of cancer survival (Figure 1). Variation in survival Much of the global variation in survival is likely to be attributable to differences in access to diagnostic and treatment services, and lack of investment in health resources3. This is also true for children: about 80% of childhood cancers arise in low-income countries, where low survival is associated with failure either to start treatment, or to complete it, in up to 60% of cases4. Variation in survival within Europe is associated with national wealth (gross domestic product), total national expenditure on health and the level of investment in health technology such as CT scanners5,6. International differences in survival can be viewed through the same lens as the differences in survival within a given country between rich and poor7,8 or insured and under-insured9 patients. Survival also varies widely between countries of low- and middle-income10. The priorities for improving outcomes differ between these economic groups of countries11. Cancer control plans Inequalities in cancer survival revealed by the EUROCARE studies12-14 are partly responsible for the re-appearance of cancer control on the political agenda of the European Union15-17. Survival trends have also provided an instructive backdrop for the evaluation of cancer control strategies in Europe and the USA18. Today, some national cancer plans are explicitly focused on improving survival. Within the last 15 years, also, international disparities in survival have underpinned cancer plans in Denmark (2005)19, Northern Ireland (1996)20, England (2000, 2007)21,22, Wales (2006)23, Victoria (Australia) (2008)24 and Sweden (2009)25. Cancer survival trends are now also being used to evaluate the effectiveness of national cancer plans once they have been implemented, by assessing their contribution to improving overall survival26,27 or reducing socioeconomic inequalities in survival28. Global surveillance of cancer survival Population-based cancer survival provides one measure of progress in cancer control. It is important to evaluate patterns and trends in incidence and mortality alongside those for survival29. Comparisons of incidence, survival and mortality have been published for many cancers in Europe30,31, and for Europe, Australia and Canada32, but not worldwide. Where possible, incidence, survival and mortality trends will be compared for countries participating in CONCORD-2, to help improve the interpretation of survival comparisons29,30,32,33. Reliable information on global trends and disparities in cancer patient survival can be expected to help focus debate on reducing geographic and racial or ethnic inequalities11. Long-term surveillance of worldwide trends in cancer incidence has provided information for aetiological research and the basis of prevention and screening since the 1960s34,35. We can predict that continuous, global surveillance of cancer survival will become equally valuable: a reliable information source for cancer patients and researchers, a stimulus for change in health policy and health care systems, and a key metric for the global surveillance of cancer control. Global surveillance of cancer survival is seen as important by many national and international agencies (Figure 2). At the World Cancer Congress in Geneva in 2008, the Union for International Cancer Control (UICC) updated the World Cancer Declaration36,37, with 11 ambitious goals to be achieved by 2020, including: “there will be major improvements in cancer survival rates… in all countries”. UICC is committed to providing progress reports every two years. The CONCORD programme for surveillance of cancer survival supports several of the goals in the UICC World Cancer Declaration (Figure 3). The Organisation for Economic Co-operation and Development (www.oecd.org), Paris, endorses the CONCORD programme, which will provide cancer survival information for 30 of its 34 Member States (Figure 4).