Clinical trial enrollment of children with cancer in Canada

On this page

• Data Sources
• Limitations
• Methodology

Data Sources

The graphs and tables were created using data from the Cancer in Young People in Canada program (CYP-C).

Cancer in Young People in Canada (CYP-C)

The CYP-C program collects health and treatment information on each child/youth under the age of 19 diagnosed with cancer and presenting at 1 of the 16 hematology, oncology, and stem cell transplant oncology programs in Canada. Each case registered in CYP-C is followed up to five years from the date of diagnosis.

There are two broad methods of data collection:

• In Ontario, the Pediatric Oncology Group of Ontario (POGO) has maintained a population-based registry of incident cancer cases since 1985, diagnosed or treated in one of the five pediatric oncology centres in the province. The Pediatric Oncology Group of Ontario Networked Information System (POGONIS) shares this information with the Public Health Agency of Canada through a data sharing agreement.
• In all other Canadian jurisdictions, data are abstracted directly from patient medical charts by clinical research associates and entered into a secure electronic data entry and management tool (known as eCYP). Data are then collated at the Public Health Agency of Canada in Ottawa, Ontario.

Research ethics boards at the Public Health Agency of Canada and all pediatric oncology centres outside of Ontario participating in direct data collection have permitted CYP-C to collect detailed data on every eligible child, creating a population-based surveillance system.

Data was extracted from CYP-C on August 27, 2024, and from POGONIS on August 28, 2024.

Note, data from the Centre hospitalier universitaire de Sherbrooke (CHUS) and the Saskatchewan Cancer Agency are not complete beyond 2015 and 2020, respectively.

Data validation and completeness

Comparisons of incidence cases in CYP-C to the Canadian Cancer Registry (CCR) data show that very few childhood cancer cases (aged 0 to 14 years) are treated outside of pediatric oncology centres (Mitra et al., 2015).

Limitations of the data

This interactive report contains some limitations:

1. Given the relative rarity of some cancers, the proportions presented in this report should be interpreted with caution as it can be difficult to distinguish differences based on random fluctuation from true differences in the underlying proportion when the number of cases is small (e.g., fewer than 20 cases).
2. A small proportion of children had missing information on initial treatment plan start dates. If available, treatment plan start dates were imputed using data about other treatment occurring within 30 days of diagnosis. If no additional dates were available, children were excluded.

Methodology

Overview

Children diagnosed with cancer, between 2001 and 2021, with treatment plan information, are included in the interactive report. As CYP-C did not collect data on adolescents (15 to 19 years old) prior to 2015, this analysis focuses on children under 15 years old.

Cases without a diagnosis listed in the International Classification of Childhood Cancer, 3rd Edition (ICCC-3) or with a relapse prior to their initial treatment plan were excluded. Children with missing information on initial treatment plan start date or treatment plan description were also excluded.

Non-overlapping 95% confidence intervals were used to infer statistically significant differences in data estimates. Only statistically significant findings are highlighted in the text description. The descriptive analyses presented in this interactive report do not control for potential confounders. Patient outcomes are also not included and outside the scope of this interactive report.

Definitions

• Sex: The sex of the child.
• Age: The age group of the child at the time of their diagnosis: <1 year, 1 to 4 years, 5 to 9 years, and 10 to 14 years.
• Region: The home region of the child at the time of their cancer diagnosis: Prairies (Manitoba, Saskatchewan, and Alberta); Atlantic (Nova Scotia, New Brunswick, Prince Edward Island, and Newfoundland and Labrador); Territories (Yukon, Northwest Territories, and Nunavut); and the provinces of British Columbia, Quebec, and Ontario.
• Year of Diagnosis: The year of a child’s cancer diagnosis.
• Cancer and cancer subtype: The first cancer diagnosis of the child. See Childhood cancer classification below for more information.
• Neighbourhood income quintile: The child’s neighbourhood before-tax income quintile, based on their postal code at time of diagnosis: highest quintile, middle-high quintile, middle quintile, middle-low quintile, and lowest quintile. Quintiles were generated by linking residential postal code at diagnosis with the appropriate vintage of the Postal Code Conversion File Plus (PCCF+). Note, neighbourhood income quintile may not reflect the socioeconomic status of children and their families.
• Urban and rural/remote: Based on a child’s postal code at time of diagnosis: urban or rural/remote. Rural/remote postal codes are identifiable by the presence of a zero (0) in the second position of the forward sortation area (FSA) code. Urban postal codes are composed of FSAs with numerals 1 to 9 in the second position of the code.
• Distance to treatment centre: The distance between the child’s postal code at the time of diagnosis to the centre providing cancer treatment, grouped as less than 200 kilometres (km), and more than or equal to 200 km. Distances reflect the difference between the treatment centre’s latitude and longitude and the latitude and longitude of the place of residence. Distances were generated by linking residential postal code at diagnosis with the appropriate vintage of the Postal Code Conversion File Plus (PCCF+).

Indicators

Indicators are presented as rounded counts and proportions with 95% confidence intervals (CI).

Enrollment on a clinical trial for initial treatment: Children with an initial treatment plan indicating “Registered on a clinical trial protocol” are classified as enrolled (Pole et al., 2017).

A protocol involves precise and detailed guidelines for a course of medical treatment. Federal regulations require clinical trials to be reviewed and approved by a Research Ethics Board prior to patients being enrolled. Patients must be officially registered with the research group that is conducting the trial.

Other possible treatment plans include “Not registered and following a clinical trial protocol”, “Not registered and not following a clinical trial (including individualized treatment plans and standard of care)”, and “Observation alone, not on a clinical trial”.

The data presented only include clinical trial enrollment during the initial treatment, typically at or close to the time of diagnosis. Clinical trial enrollment at refractory disease or relapse is not explored.

Reason for non-enrollment: The reason that a child was not enrolled in a clinical trial for initial treatment. The indicator reports the number and proportion not enrolled because no trial was available at the time for the given diagnosis at the child’s treatment centre.

Only patients who were not enrolled in a clinical trial for initial treatment are included in this indicator. Patients on palliative care are not included in this indicator. As the POGONIS database did not consistently collect reasons for non-enrollment throughout our study period (2001 to 2021), only data from the 12 non-Ontario centers were included.

Note, data about trial access and availability in this population are not available, and availability likely influences enrollment on clinical trials. There are several possible reasons why a trial may be unavailable. It may reflect a lack of any trial for a child’s diagnosis, or a trial was available but not activated at the centre because of regulatory/ethics barriers or delays, or the centre may have chosen not to open an available study.

Childhood cancer classification

Cancer and tumour types were defined using the International Classification of Childhood Cancer, 3^rd Edition (ICCC-3). The ICCC-3 is a diagnostic classification system for childhood cancer based on tumour morphology and primary site, with a greater emphasis on morphology as compared to the classification of cancers for adults. The ICCC-3 is coded using ICD-O-3, based on the definitions presented in Steliarova-Foucher et al.

The ICCC is coded using ICD-O-3, based on the definitions presented in Steliarova-Foucher et al. (2017), known as ICCC, Third Edition based on ICD-O-3/IARC 2017. Multiple primaries were defined according to the International Agency for Research on Cancer’s (IARC) rules.

Cancer types and subtypes groupings

• Leukemia
  • I (a) Lymphoid leukemias
  • I (b) Acute myeloid leukemias
  • Other:
    • I (c) Chronic myeloproliferative diseases
    • I (d) Myelodysplastic syndrome and other myeloproliferative diseases
    • I (e) Unspecified/other specified leukemias
• Lymphoma
  • II (a) Hodgkin lymphomas
  • II (b) Non-Hodgkin lymphomas (except Burkitt lymphoma)
  • II (c) Burkitt lymphoma
  • Other:
    • II (d) Miscellaneous lymphoreticular neoplasms
    • II (e) Unspecified lymphomas
• Central Nervous System (CNS) Tumours
  • III (a) Ependymomas and choroid plexus tumor
  • III (b) Astrocytomas
  • III (c) Intracranial and intraspinal embryonal tumor
  • Other:
    • III (d) Other gliomas
    • III (e) Other specified intracranial and intraspinal neoplasms
• Non-CNS Solid Tumours
  • IV Neuroblastoma and other peripheral nervous cell tumors
  • VI (a) Nephroblastoma and other non-epithelial renal tumors
  • VII (a) Hepatoblastoma
  • VIII (a) Osteosarcoma
  • VIII (c) Ewing sarcoma
  • IX (a) Rhabdomyosarcoma
  • Other:
    • Retinoblastoma
    • Renal tumors (other than nephroblastoma)
    • Hepatic tumors (other than hepatoblastoma)
    • Malignant bone tumors (other than osteosarcomas and Ewing sarcoma)
    • Soft tissue and other extraosseous sarcomas (other than rhabdomyosarcomas)
    • Germ cell tumors, trophoblastic tumors and neoplasms of gonads
    • Other malignant epithelial neoplasms and malignant melanomas
    • Other and unspecified malignant neoplasms

Suppression

To ensure confidentiality, counts between 1 and 4 are suppressed and identified by “suppr.” in the data tables. Proportions based on counts between 1 and 4 are not reported.

In addition, case counts are rounded either up or down to a multiple of 5 using unbiased random rounding. Note, if the rounded count is zero, this means the actual number is zero. Proportions are calculated using the rounded counts.

Suggested Citation

Centre for Surveillance and Applied Research, Public Health Agency of Canada. Clinical Trial Enrollment of Children with Cancer in Canada. Health Infobase. Ottawa (ON): Public Health Agency of Canada, 2025.