How Tumor Stage Affects Childhood Cancer Survival: Insights from the BENCHISTA Study

Childhood cancer remains one of the most challenging areas in pediatric medicine, with survival outcomes varying significantly across countries and regions. While advancements in diagnosis and treatment have improved outcomes over the past decades, disparities persist even among high-income nations. The recent BENCHISTA (International Benchmarking of Childhood Cancer Survival by Stage) study, published in JAMA Network Open, provides critical insights into how tumor stage at diagnosis influences survival in six common childhood solid tumors and sheds light on geographic variations in outcomes.

What Is the BENCHISTA Study?

The BENCHISTA project is a population-based retrospective cohort study designed to investigate international differences in childhood cancer survival by tumor stage. Researchers collected data on 9,883 children diagnosed with one of six childhood solid tumors—neuroblastoma, Wilms tumor, medulloblastoma, osteosarcoma, Ewing sarcoma, and rhabdomyosarcoma—between 2014 and 2017 from 73 cancer registries in 27 countries, including Europe, Australia, Brazil, Canada, and Japan.

A key feature of this study was the use of the Toronto Stage Guidelines (TG), an internationally recognized framework for recording tumor stage at diagnosis in pediatric cancers. Staging is a crucial prognostic factor, as it informs treatment intensity, therapeutic decisions, and overall survival expectations. However, unlike adult cancers, standardized staging has historically been inconsistent for pediatric cancers, making population-level comparisons difficult. BENCHISTA addressed this gap by supporting cancer registries with standardized training, quality audits, and access to expert guidance for stage assignment.

Tumor Stage and Survival Outcomes

Across all six tumor types, the study confirmed that higher tumor stage at diagnosis is associated with lower survival. For instance, three-year overall survival (OS) in Wilms tumor was 95%, while survival in osteosarcoma was 75%. Neuroblastoma and medulloblastoma had intermediate survival rates of 83% and 79%, respectively, while Ewing sarcoma and rhabdomyosarcoma showed survival rates of 78% and 77%.

Stage-specific survival varied considerably. For rhabdomyosarcoma, patients with localized disease had a three-year OS of 95%, whereas those with metastatic disease had only 45% survival. In contrast, Wilms tumor showed a smaller difference, with 99% survival in stage I and 87% in stage IV, reflecting the generally favorable prognosis of this cancer type. These findings underscore the critical importance of early detection and accurate staging in improving childhood cancer outcomes.

Geographic Variation in Survival

One of the most significant contributions of the BENCHISTA study is its analysis of geographic differences in survival. The study grouped European countries into Central, Eastern, Northern, Southern, and the UK and Ireland regions while considering non-European countries individually.

Key findings include:

• Wilms tumor and osteosarcoma: No significant survival differences were observed between regions, likely due to standardized treatment protocols and the inherently favorable prognosis of Wilms tumor.
• Ewing sarcoma and medulloblastoma: Significant regional survival differences were observed, particularly in Eastern Europe and the UK and Ireland. For Ewing sarcoma, three-year OS for metastatic cases was significantly lower in Eastern Europe and the UK and Ireland compared with Central Europe. Medulloblastoma also showed worse outcomes in Eastern Europe after adjustment for age and sex.
• Neuroblastoma and rhabdomyosarcoma: In these tumors, differences in stage distribution at diagnosis partly explained survival disparities. For example, the UK and Ireland had a higher proportion of advanced-stage neuroblastoma, while Eastern Europe had more advanced rhabdomyosarcoma cases, contributing to observed survival gaps.

Interestingly, in some regions, adjusting for stage unexpectedly revealed worse survival compared with Central Europe. For example, in Eastern Europe, a higher proportion of localized neuroblastoma cases suggested potential underdiagnosis of metastatic disease due to limited access to sensitive staging tools like iodine meta-iodobenzylguanidine scans. Similarly, medulloblastoma cases in Southern Europe appeared understaged due to delayed or absent cerebrospinal fluid testing, which may result in undertreatment and poorer outcomes.

Implications for Early Diagnosis

The BENCHISTA findings highlight the crucial role of early diagnosis in childhood cancer outcomes. Delays in identifying tumors or incomplete staging can significantly affect survival, especially for aggressive cancers like Ewing sarcoma, medulloblastoma, and rhabdomyosarcoma. Early detection enables timely intervention, appropriate treatment intensity, and improved prognosis.

National health systems can benefit from these insights by:

1. Promoting awareness: Educating healthcare providers and families about early warning signs of childhood cancers can reduce diagnostic delays.
2. Standardizing diagnostic protocols: Ensuring universal access to advanced imaging and staging procedures can improve accuracy and reduce survival disparities.
3. Strengthening collaboration: Close cooperation between cancer registries and clinicians allows for accurate data collection, which is critical for monitoring outcomes and identifying areas for improvement.

The Role of Population-Based Cancer Registries

Population-based cancer registries (CRs) were central to the success of the BENCHISTA project. Registries provide structured, standardized data collection across regions, enabling researchers to identify trends and disparities that might otherwise go unnoticed. By incorporating Toronto Stage Guidelines, registries can now systematically record tumor stage, allowing for more accurate international comparisons.

BENCHISTA also demonstrated that CRs can overcome challenges like missing or incomplete data through expert training, quality assurance audits, and support mechanisms. This approach provides a template for other countries seeking to monitor childhood cancer outcomes and implement interventions to improve survival.

Factors Beyond Stage

While tumor stage is a key predictor of survival, BENCHISTA shows that it does not explain all international differences. For instance, Ewing sarcoma survival in Eastern Europe and the UK and Ireland remained significantly lower than Central Europe even after adjusting for stage. This suggests other contributing factors, including:

• Treatment differences: Access to standardized protocols and specialized centers can vary, particularly for patients with metastatic or complex disease.
• Tumor biology: Genetic and molecular characteristics may influence aggressiveness and response to therapy.
• Healthcare access: Socioeconomic status, geographic location, and availability of specialized pediatric oncology services impact outcomes.
• Diagnostic intensity: Higher incidence regions may detect more early-stage cases, indirectly improving survival through stage distribution.

Understanding these factors is essential for designing interventions that reduce survival disparities. BENCHISTA Phase 2 will explore these elements, including nonstage prognostic factors, treatment received, and causes of death.

Strengths and Limitations of the Study

BENCHISTA has several strengths:

• Large-scale international collaboration: Data from 73 registries across 27 countries provide a comprehensive overview.
• Standardized staging: Using Toronto Stage Guidelines ensures comparability of stage data across regions.
• Population-based approach: Inclusion of all incident cases within participating regions reduces selection bias and allows for accurate survival estimates.

However, the study also has limitations:

• Limited follow-up: Three-year survival was analyzed, which may not capture long-term outcomes.
• Incomplete data from some regions: Certain countries could not provide data for all six tumors due to access limitations or national regulations.
• Small case numbers for rare tumors: Low incidence limited statistical power for some analyses.
• Potential unmeasured confounders: Socioeconomic factors, healthcare access, and tumor biology were not fully captured and may influence survival.

Despite these limitations, BENCHISTA represents a significant step forward in understanding the global landscape of childhood cancer survival.

Recommendations for Policymakers and Clinicians

The findings of BENCHISTA have important implications for health systems, policymakers, and clinicians. Key recommendations include:

1. Prioritize early detection: Screening programs, public awareness campaigns, and timely referral pathways can reduce late-stage diagnoses.
2. Standardize staging and treatment: Implementing universal staging guidelines and harmonized treatment protocols can minimize regional disparities.
3. Enhance data infrastructure: Strengthening cancer registries and ensuring high-quality, complete data collection enables continuous monitoring of outcomes.
4. Address healthcare inequalities: Ensuring equitable access to advanced diagnostic tools and specialized pediatric oncology care is essential.
5. Encourage international collaboration: Sharing data, best practices, and expertise between countries can improve survival for all children.

Conclusion

The BENCHISTA study provides compelling evidence that tumor stage at diagnosis is a major determinant of survival in childhood solid tumors and contributes to international disparities in outcomes. While some regional differences can be explained by stage distribution, others suggest the influence of additional factors such as treatment variation, healthcare access, and diagnostic intensity.

For policymakers, clinicians, and parents, these findings underscore the importance of early detection, standardized staging, and international collaboration. By implementing strategies to reduce diagnostic delays, improve access to accurate staging, and ensure consistent treatment protocols, countries can improve survival for children with cancer worldwide.

Sources

1. Botta L, Didonè F, Lopez-Cortes A, et al. Stage at Diagnosis and International Survival Variation in Childhood Tumors in the BENCHISTA Study. JAMA Netw Open. 2026;9(2):e2556747. doi:10.1001/jamanetworkopen.2025.56747
2. Toronto International Pediatric Cancer Stage Guidelines. Available at:
3. EUROCARE-5 Study Group. Childhood Cancer Survival in Europe: Results from EUROCARE-5. Lancet Oncol. 2014;15(1):23–34.
4. Steliarova-Foucher E, et al. International Incidence of Childhood Cancer, 2001-2010. Int J Cancer. 2017;141(4):664–675.

Disclaimer

This blog is for informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider for any concerns regarding childhood cancer or treatment decisions.