Every year, estimates suggest that almost 400,000 new cases of childhood cancer occur but current records account for just over 220,000 of them, according to an analysis published in the journal The Lancelot Oncology. Of those, children in low- and middle-income countries are disproportionately burdened.
Researchers analyzed childhood cancer registries in 200 countries and combined their findings with data compiled by the World Health Organization (WHO) and Unicef. They found that more than half of total childhood cancer cases in Africa, South Central Asia, and the Pacific Islands go undiagnosed. For comparison, just 3 percent of childhood cancer incidents are left undiagnosed in North America and Europe.
"Our model suggests that nearly one in two children with cancer are never diagnosed and may die untreated," said study author Zachary Ward in a statement. "Accurate estimates of childhood cancer incidence are critical for policymakers 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."
Cancer is the leading cause of death for children, according to the WHO. In high-income countries, more than 80 percent of children with cancer are cured, but that number drops to just 20 percent in low- and middle-income countries. Though childhood cancer around the world is generally declining, the authors note that an estimated 92 percent of new cases probably occur in low and middle-income countries. By 2030, there will be an estimated 6.7 million new cases of childhood cancer, 2.9 million of which will be missed if the performance of health systems don't improve.
"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," said senior author Rifat Atun. Strengthened health systems around the world, the authors note, would bring well-functioning healthcare facilities to provide “timely diagnosis, referral, and treatment” as well as expand cancer registration in countries that lack them.
The authors note that their study is limited by cancer registry data that is available and predictions in Africa could be influenced by the country’s representation. As well, the study assumes that all diagnosed cases are accurately recorded, which isn’t always the case.