Earlier diagnosis could play a key role in improving childhood cancer survival and reducing inequalities between countries, according to new research.
The study, published in JAMA Network Open, is the first to show that differences in tumour stage at diagnosis may help explain why childhood cancer survival varies between some European regions and tumour types.
Researchers analysed data from 9,883 children recorded by 73 population-based cancer registries across 27 countries, mainly in Europe.
The children were diagnosed between 2014 and 2017 with one of six cancers: neuroblastoma, Wilms tumour, medulloblastoma, osteosarcoma, Ewing sarcoma and rhabdomyosarcoma.
Across all six cancers, three-year survival was strongly linked to tumour stage at diagnosis, with survival decreasing as stage increased.
Using Central Europe as the benchmark, made up of Austria, Belgium, France, Germany, Switzerland and the Netherlands, researchers found significant regional variation in three-year survival for four of the cancers studied.
For neuroblastoma, a tumour that commonly develops in the adrenal glands and other sites, children in the UK and Ireland had lower survival rates than those in Central Europe.
The researchers said this difference could be explained by the cancer being diagnosed at a relatively later stage in the UK and Ireland.
However, for Ewing sarcoma, a type of bone tumour, lower survival in Eastern Europe and in the UK and Ireland compared with Central Europe was not explained by later diagnosis.
Instead, the difference was seen only among patients whose tumour had spread.
The researchers said further investigation is needed into other possible factors, including where the cancer had spread and whether treatment approaches differ for children with metastatic disease.
Until now, a lack of reliable data on tumour stage at diagnosis has made it difficult to use cancer registry data to understand why childhood cancer survival varies between countries.
The International Benchmarking of Childhood Cancer Survival by Stage project, known as BENCHISTA, has improved how national cancer registries collect childhood cancer data so that it can be compared reliably.
The project involved 23 European countries, including the UK, as well as Brazil, Canada, Australia and Japan.
Through an agreement that took 18 months to broker, participating countries improved their data collection methods to ensure at least 90 per cent of childhood cancer cases had tumour stage recorded in a consistent way.
The researchers used the Toronto Childhood Cancer Stage Guidelines, which were developed in the 2010s.
The findings mean researchers are now better placed to understand why childhood cancer survival differs between regions and to guide efforts to improve outcomes.
The next phase of BENCHISTA will examine other factors, including treatment differences, access to specialist care and health system variation.
It will also report five-year survival, the standard epidemiological cancer outcome measure.
Joint senior author Professor Kathy Pritchard-Jones, from UCL Great Ormond Street Institute of Child Health, said: “By analysing population-level data from cancer registries across many countries, we have been able to better understand why childhood cancer survival still differs internationally.
“Our findings show that diagnosing cancer earlier and accurately assessing how far it has spread can make a meaningful difference to survival for many children.
“At the same time, the study highlights that early diagnosis alone will not address all disparities, and further work is needed to understand and tackle other contributing factors.
“We have, for the first time, provided unbiased, population-level evidence for later diagnosis of some childhood cancers in the UK and Ireland.”
Corresponding author Dr Laura Botta, a statistician in the Evaluative Epidemiology Unit at INT, said the project highlighted the importance of high-quality data and stronger cooperation between clinicians and population-based cancer registries.
She said: “Our project not only emphasises the importance of gathering high-quality data and strengthening cooperation between clinicians and population-based cancer registries but also serves as a key tool to uncover the reasons for survival differences between countries for children with cancer.
“Our results provide the first population-based and international evidence that, in some countries, paediatric tumours are diagnosed at more advanced stages compared to a group of European countries with the most consistent practices, while in others, staging procedures do not meet recommended standards — clearly impacting prognosis.
“We hope these findings will help guide health policies that are vital to saving lives.”
The study was funded by Children with Cancer UK and Associazione Italiana per la Ricerca sul Cancro.
Professor Pritchard-Jones and Dr Angela Lopez-Cortes also received funding from the National Institute for Health and Care Research Great Ormond Street Hospital Biomedical Research Centre.
Gavin Maggs, chief executive of Children with Cancer UK, said: “We are proud to have funded this important study, which provides powerful new evidence on the role that early diagnosis plays in improving childhood cancer survival.
“By bringing together experts from around the world, BENCHISTA shows how internationally comparable data can guide global efforts to ensure children are diagnosed as early as possible and receive the right care at the right time.
“Cancer does not recognise borders, and neither should the chances of surviving it.”
Ashley Ball-Gamble, chief executive of CCLG: The Children & Young People’s Cancer Association, said: “This study confirms that, for some childhood cancers, diagnosis in the UK still takes longer than it should.
“Because delays can affect a child’s chance of survival, campaigning for faster recognition is more important than ever.
“Our Child Cancer Smart campaign aims to tackle these delays by giving GPs the tools to identify cancer sooner — and by helping parents understand the warning signs.”
Angela Polanco, the project’s patient and public involvement lead, whose daughter Bethany was diagnosed with Wilms tumour, said the study showed the need for timely diagnosis and specialist care for all children with cancer.
She said: “This study provides clear evidence that we need to do more to ensure children affected by cancer have access to timely and accurate diagnosis, appropriate first-line treatment, and specialist care, wherever they live.
“Collecting and analysing this information at a population level is a crucial step towards reducing inequalities and improving survival for children with cancer.”
Wilms tumour is a kidney tumour, medulloblastoma is a brain tumour, rhabdomyosarcoma is a muscle tumour, and osteosarcoma and Ewing sarcoma are bone tumours.