Washington: A new study, published in The Lancet Oncology journal estimates there are almost 4 lakh new cases of cancer annually, while current records only count around 2,00,000.
The new study model makes predictions for 200 countries and estimates that undiagnosed cases could account for more than half of the total in Africa, South Central Asia and the Pacific Islands.
Speaking about the study, lead author Zachary Ward said, “Our model suggests that nearly one in two children with cancer are never diagnosed and may die untreated.”
Ward further added, “Accurate estimates of childhood cancer incidence are critical for policy makers to help them set healthcare priorities and to plan for effective diagnosis and treatment of all children with cancer. While under-diagnosis has been acknowledged as a problem, this model provides specific estimates that have been lacking.”
The new model developed for this study, the Global Childhood Cancer microsimulation model, incorporates data from cancer registries in countries where they exist, combining it with data from the World Health Organisation’s Global Health Observatory, demographic health surveys and household surveys developed by Unicef.
The model was calibrated to data from public registries and adjusts for under-diagnosis due to weaknesses in national health systems.
The study estimates that in 2015 there were 3,97,000 childhood cancer cases globally, compared to 2,24,000 that were recorded as diagnosed. This suggests that 43 per cent (1,72,000 cases) of global childhood cancer cases were undiagnosed. While in most regions of the world, the number of new childhood cancer cases is declining or stable, the authors estimate that 92 per cent of all new cases occur in low and middle-income countries, a higher proportion than previously thought.
The most common childhood cancer in most regions of the world in 2015 was found to be acute lymphoblastic leukaemia, with the notable exception of sub-Saharan Africa.
There were around 75,000 new cases globally, including nearly 700 in North Europe, over 1,500 in West Africa, over 3,500 in East Africa and nearly 30,000 in South Central Asia. In East and West Africa, Burkitt’s lymphoma was more common, with over 4,000 cases in East Africa and over 10,000 in West Africa.
For example, there were around 1,000 cases in the Democratic Republic of the Congo and Ethiopia, while only around 20 in the UK.
Speaking about the study, author Professor Rifat Atun said, “Health systems in low-income and middle-income countries are clearly failing to meet the needs of children with cancer. Universal health coverage, a target of United Nations Sustainable Development Goals, must include cancer in children as a priority to prevent needless deaths.”
The authors estimate that between 2015 and 2030 there will be 6.7 million new cases of childhood cancer worldwide. Of these, 2.9 million cases will be missed if the performance of health systems does not improve. The authors hope that their findings will help guide new policies in health systems to improve diagnosis and management of childhood cancers.