International benchmarking of childhood cancer survival by stage at diagnosis: The BENCHISTA project protocol

BACKGROUND: Several studies have shown significant variation in overall survival rates from childhood cancer between countries, using population-based cancer registry (PBCR) data for all cancers combined and for many individual tumour types among children. Without accurate and comparable data on Tumour stage at diagnosis, it is difficult to define the reasons for these survival differences. This is because measurement systems designed for adult cancers do not apply to children's cancers and cancer registries often hold limited information on paediatric tumour stage and the data sources used to define it. AIMS: The BENCHISTA project aims to test the application of the international consensus "Toronto Staging Guidelines" (TG) for paediatric tumours by European and non-European PBCRs for six common paediatric solid tumours so that reliable comparisons of stage at diagnosis and survival rates by stage can be made to understand any differences. A secondary aim is to test the data availability and completeness of collection of several 'Toronto' consensus non-stage prognostic factors, treatment types given, occurrence of relapse/progression and cause of death as a descriptive feasibility study. METHODS: PBCRs will use their permitted data access channels to apply the Toronto staging guidelines to all incident cases of six solid childhood cancers (medulloblastoma, osteosarcoma, Ewings sarcoma, rhabdomyosarcoma, neuroblastoma and Wilms tumour) diagnosed in a consecutive three-year period within 2014-2017 in their population. Each registry will provide a de-identified patient-level dataset including tumour stage at diagnosis, with only the contributing registry holding the information that would be needed to re-identify the patients. Where available to the registry, patient-level data on 'Toronto' non-stage prognostic factors, treatments given and clinical outcomes (relapse/progression/cause of death) will be included. More than 60 PBCRs have been involved in defining the patient-level dataset items and intend to participate by contributing their population-level data. Tumour-specific on-line training workshops with clinical experts are available to cancer registry staff to assist them in applying the Toronto staging guidelines in a consistent manner. There is also a project-specific help desk for discussion of difficult cases and promotion of the CanStaging online tools, developed through the International Association of Cancer Registries, to further ensure standardisation of data collection. Country-specific stage distribution and observed survival by stage at diagnosis will be calculated for each tumour type to compare survival between countries or large geographical regions. DISCUSSION: This study will be promote and enhance the collection of standardized staging data for childhood cancer by European and non-European population-based cancer registries. Therefore, this project can be seen as a feasibility project of widespread use of Toronto Staging at a population-level by cancer registries, specifying the data sources used and testing how well standardized the processes can be. Variation in tumour stage distribution could be due to real differences, to different diagnostic practices between countries and/or to variability in how cancer registries assign Toronto stage. This work also aims to strengthen working relationships between cancer registries, clinical services and cancer-specific clinical study groups, which is important for improving patient outcomes and stimulating research

Cancer data quality and harmonization in Europe: the experience of the BENCHISTA Project – international benchmarking of childhood cancer survival by stage

Introduction: Variation in stage at diagnosis of childhood cancers (CC) may explain differences in survival rates observed across geographical regions. The BENCHISTA project aims to understand these differences and to encourage the application of the Toronto Staging Guidelines (TG) by Population-Based Cancer Registries (PBCRs) to the most common solid paediatric cancers. Methods: PBCRs within and outside Europe were invited to participate and identify all cases of Neuroblastoma, Wilms Tumour, Medulloblastoma, Ewing Sarcoma, Rhabdomyosarcoma and Osteosarcoma diagnosed in a consecutive three-year period (2014-2017) and apply TG at diagnosis. Other non-stage prognostic factors, treatment, progression/recurrence, and cause of death information were collected as optional variables. A minimum of three-year follow-up was required. To standardise TG application by PBCRs, on-line workshops led by six tumour-specific clinical experts were held. To understand the role of data availability and quality, a survey focused on data collection/sharing processes and a quality assurance exercise were generated. To support data harmonization and query resolution a dedicated email and a question-and-answers bank were created. Results: 67 PBCRs from 28 countries participated and provided a maximally de-personalized, patient-level dataset. For 26 PBCRs, data format and ethical approval obtained by the two sponsoring institutions (UCL and INT) was sufficient for data sharing. 41 participating PBCRs required a Data Transfer Agreement (DTA) to comply with data protection regulations. Due to heterogeneity found in legal aspects, 18 months were spent on finalizing the DTA. The data collection survey was answered by 68 respondents from 63 PBCRs; 44% of them confirmed the ability to re-consult a clinician in cases where stage ascertainment was difficult/uncertain. Of the total participating PBCRs, 75% completed the staging quality assurance exercise, with a median correct answer proportion of 92% [range: 70% (rhabdomyosarcoma) to 100% (Wilms tumour)]. Conclusion: Differences in interpretation and processes required to harmonize general data protection regulations across countries were encountered causing delays in data transfer. Despite challenges, the BENCHISTA Project has established a large collaboration between PBCRs and clinicians to collect detailed and standardised TG at a population-level enhancing the understanding of the reasons for variation in overall survival rates for CC, stimulate research and improve national/regional child health plans

Cancer data quality and harmonization in Europe: the experience of the BENCHISTA Project – international benchmarking of childhood cancer survival by stage

IntroductionVariation in stage at diagnosis of childhood cancers (CC) may explain differences in survival rates observed across geographical regions. The BENCHISTA project aims to understand these differences and to encourage the application of the Toronto Staging Guidelines (TG) by Population-Based Cancer Registries (PBCRs) to the most common solid paediatric cancers.MethodsPBCRs within and outside Europe were invited to participate and identify all cases of Neuroblastoma, Wilms Tumour, Medulloblastoma, Ewing Sarcoma, Rhabdomyosarcoma and Osteosarcoma diagnosed in a consecutive three-year period (2014-2017) and apply TG at diagnosis. Other non-stage prognostic factors, treatment, progression/recurrence, and cause of death information were collected as optional variables. A minimum of three-year follow-up was required. To standardise TG application by PBCRs, on-line workshops led by six tumour-specific clinical experts were held. To understand the role of data availability and quality, a survey focused on data collection/sharing processes and a quality assurance exercise were generated. To support data harmonization and query resolution a dedicated email and a question-and-answers bank were created.Results67 PBCRs from 28 countries participated and provided a maximally de-personalized, patient-level dataset. For 26 PBCRs, data format and ethical approval obtained by the two sponsoring institutions (UCL and INT) was sufficient for data sharing. 41 participating PBCRs required a Data Transfer Agreement (DTA) to comply with data protection regulations. Due to heterogeneity found in legal aspects, 18 months were spent on finalizing the DTA. The data collection survey was answered by 68 respondents from 63 PBCRs; 44% of them confirmed the ability to re-consult a clinician in cases where stage ascertainment was difficult/uncertain. Of the total participating PBCRs, 75% completed the staging quality assurance exercise, with a median correct answer proportion of 92% [range: 70% (rhabdomyosarcoma) to 100% (Wilms tumour)].ConclusionDifferences in interpretation and processes required to harmonize general data protection regulations across countries were encountered causing delays in data transfer. Despite challenges, the BENCHISTA Project has established a large collaboration between PBCRs and clinicians to collect detailed and standardised TG at a population-level enhancing the understanding of the reasons for variation in overall survival rates for CC, stimulate research and improve national/regional child health plans

International benchmarking of stage at diagnosis for six childhood solid tumours (the BENCHISTA project): a population-based, retrospective cohort study

Background: International variation in childhood cancer survival might be explained by differences in stage at diagnosis, among other factors. As part of the BENCHISTA project, we aimed to assess geographical variation in tumour stage at diagnosis through the application, by population-based cancer registries working with clinicians, of the international consensus Toronto Childhood Cancer Stage Guidelines. Methods: This population-based, retrospective cohort study involved 73 cancer registries from 23 European countries, Australia, Brazil, Japan, and Canada. Participating cancer registries applied the Toronto Guidelines to stage all incident cases of six childhood solid tumours—neuroblastoma, medulloblastoma, and Wilms tumour (age 0–14 years) and Ewing sarcoma, rhabdomyosarcoma, and osteosarcoma (age ≤19 years)—diagnosed between Jan 1, 2014, and Dec 31, 2017. Eligible cancer registries were those able to assign stage according to the Toronto Guidelines; information on the staging investigations conducted was collected where available. European countries were grouped by geographical area and non-European countries were considered individually. We used χ2 tests to compare stage distribution across these geographical areas and multivariable logistic models to estimate odds ratios (ORs) for metastatic stage at diagnosis, using central Europe (Austria, Belgium, France, Germany, the Netherlands, and Switzerland) as the comparison. Sensitivity analyses were conducted to overcome potential bias from non-random missing stage information for some geographical areas and cancer types. Findings: Data from 10 937 patients with cancer (6031 [55·1%] male and 4906 [44·9%] female) were analysed. Tumour staging was complete for 93·1% (10 180 of 10 937) of patients, ranging from 88·7% (1347 of 1518 patients) with medulloblastoma to 96·5% (1083 of 1122 patients) with Ewing sarcoma. Stage distribution differed statistically by geographical area for neuroblastoma, Wilms tumour, osteosarcoma, and rhabdomyosarcoma, but not for Ewing sarcoma or medulloblastoma. After excluding patients with missing stage information and, for the sarcomas, patients aged 18–19 years, the proportions of patients with metastases detected at diagnosis were 50·3% with neuroblastoma (1435 of 2852 patients; including 1159 [40·6%] stage M and 276 [9·7%] stage MS), 35·1% with medulloblastoma (473 of 1347 patients; stages M1–M4), 32·6% with Ewing sarcoma (335 of 1028 patients), 29·0% with rhabdomyosarcoma (368 of 1267 patients), 25·5% with osteosarcoma (345 of 1353 patients), and 18·2% with Wilms tumour (384 of 2114 patients). After adjusting by age group, significant differences in the proportions of patients with metastases detected at diagnosis were found between geographical areas for neuroblastoma, Wilms tumour, osteosarcoma, and rhabdomyosarcoma. Interpretation: Assessed at a population level, the stage at diagnosis shows significant variation between geographical areas for several childhood tumours. This finding highlights the need for earlier diagnosis and standardisation of investigations for distant metastases. To enable ongoing comparisons, further cooperation efforts are required between cancer registries and clinicians regarding the sustainable and standardised use of the Toronto Guidelines at diagnosis. Funding: Children with Cancer UK and Associazione Italiana per la Ricerca sul Cancro