Canadian Cancer Registry (CCR)

Detailed information for 2021

Status:

Active

Frequency:

Annual

Record number:

3207

The Canadian Cancer Registry (CCR) is a population-based registry that includes data collected and reported to Statistics Canada (StatCan) by each provincial/territorial cancer registry (PTCR). The person-based CCR collects information about each new primary cancer diagnosed among Canadian residents since 1992. The objective is to produce standardized and comparable incidence data that can be used to assist and support health planners and decision-makers to: identify risk factors; plan, monitor and evaluate cancer screening, treatment and control programs; and conduct research.

Data release - January 31, 2024

Description

Beginning with cases diagnosed in 1992, cancer incidence data collected by PTCRs have been reported to StatCan to populate the CCR.

The CCR falls under the governance of the Canadian Council of Cancer Registries (CCCR), a collaboration between the 13 Canadian PTCRs and the Centre for Population Health Data of StatCan. Ultimate authority and responsibility for the completeness and the quality of the data resides with the provinces and territories while StatCan is the custodian of the CCR.

The CCR is a dynamic database of all primary cancer cases diagnosed among Canadian residents since 1992. The data submitted by the PTCRs to StatCan describe the individual with the cancer and the characteristics of the cancer. Being a person-based system, the CCR contains information about the type and number of primary cancers diagnosed for each person. A person-oriented database has the advantage of being able to provide longitudinal data for each cancer patient such that a single person record exists for all tumors diagnosed during that person's lifetime.

Reference period: Calendar year

Collection period: Fifteen months after the end of the reference period.

Subjects

  • Diseases and health conditions
  • Health
  • Health care services
  • Life expectancy and deaths

Data sources and methodology

Target population

The conceptual universe of the CCR is persons whose usual place of residence is Canada (residents) or foreign citizens (non-residents) who are in Canada for a continuous period of six months or more at the time of diagnosis. The residence at the time of diagnosis is generally the place of usual residence, as stated by the diagnosed person or, as defined by the Census, "the dwelling in Canada where a person lives most of the time", regardless of where they are when diagnosed. For patients diagnosed with multiple primary tumours over time, place of residence may be different for each primary tumour.

For detailed information on CCR universe or residency guidelines, please contact Health Statistics Branch Client Services (613-951-1746 or hd-ds@statcan.gc.ca).

Instrument design

This methodology type does not apply to this statistical program.

Sampling

The CCR is a census of persons diagnosed with cancer.

Data sources

The CCR is comprised of administrative data collected under section 13 of the Statistics Act. To avoid duplication, PTCRs supply data annually to StatCan on cancer patients and new primary tumours for residents of their jurisdiction (see Target population). Since the CCR is dynamic, annual submissions by the PTCRs include additions and revisions to data submitted in previous years.

The CCCR sets the Canadian cancer standards and reporting requirements. PTCRs are expected to report the following tumours to the CCR:

- Most primary, malignant tumours (behaviour codes of 3), with exceptions for certain non-melanoma skin cancers;
- Most carcinoma in situ/intraepithelial/noninfiltrating/noninvasive tumours (behaviour codes of 2), with exceptions for cervix, prostate, colon and rectum, and certain non-melanoma skin cancers;
- Some borderline malignancies (behaviour codes of 1);
- All primary, benign tumours (behaviour codes of 0) of the meninges, brain, spinal cord, cranial nerves, other parts of the central nervous system, pituitary gland, craniopharyngeal duct, and pineal gland.

The International Classification of Diseases for Oncology 3rd edition, 2nd revision (ICD-O-3.2) was used as of diagnosis year 2021.

The CCR includes basic patient demographic information (e.g., age and sex) and detailed information on tumour characteristics and diagnosis.

For details on CCR scope, inclusions and exclusions, coding standards, and information for data users, please contact Health Statistics Branch Client Services (613-951-1746 or hd-ds@statcan.gc.ca).

Error detection

Each record submitted by a PTCR is verified to identify possible errors (e.g., unexpected values or formatting issues). Validation edits are used to verify that each field contains values that fall within the allowable range for that data element. Correlation edits are used to check the compatibility of different data elements within a record and to verify that relationships between person and tumour information are logical. Match edits are used to check key identifier fields to aid in ensuring that, where identifiable, duplicate records are not added to the CCR database. These verifications are done as data are loaded into the CCR database and any records failing one or more edits are rejected and returned to the submitting PTCR for verification and/or correction.

The CCR also performs internal record linkage to identify possible duplicate records. Once identified, PTCRs are consulted to establish patient ownership and identify records that should be removed.

Imputation

StatCan does not impute missing data on the CCR.

Estimation

This methodology type does not apply to this statistical program.

Quality evaluation

StatCan periodically produces Data Quality and Data Validation Reports that provide detailed feedback to the PTCRs on the quality of data submitted.

CCR Data Quality and Data Validation Reports are used by PTCRs to monitor the quality of their information in the CCR and meet standards for acceptance in international publications such as Cancer Incidence in Five Continents and Cancer Incidence in North America.

Disclosure control

Statistics Canada is prohibited by law from releasing any information it collects that could identify any person, business, or organization, unless consent has been given by the respondent or as permitted by the Statistics Act. Various confidentiality rules are applied to all data that are released or published to prevent the publication or disclosure of any information deemed confidential. If necessary, data are suppressed to prevent direct or residual disclosure of identifiable data.

In regard to random rounding of tabular data, the CCR rounds each cell count, independently of other cells, to a lower or higher multiple of 5; true zeros and actual counts evenly divisible by 5 are not affected. Random rounding is applied to each cell count independently. Specifically, an unbiased random rounding procedure is applied such that numbers ending in 0 or 5 are not rounded; numbers ending in a 1 or 6 are rounded up with a probability of 0.20 and down with a probability of 0.80; numbers ending in 2 or 7 are rounded up and down with probabilities of 0.40 and 0.60, respectively; numbers ending in 3 or 8 are rounded up and down with probabilities of 0.60 and 0.40, respectively; and, numbers ending in 4 or 9 are rounded up and down with probabilities of 0.80 and 0.20, respectively. Consequently, columns and rows will sum to totals only by chance. By design, differences between the rounded and actual counts will never exceed 4 and actual counts are more likely to be rounded to the nearest multiple of 5.

When calculating crude or specific rates and confidence intervals, the CCR uses the rounded count. Otherwise, the actual count can be deciphered relatively easily by using publicly available population estimates. Because age-standardized rates are more complex to calculate, involving the combining of data across multiple age strata, the CCR uses the actual age-specific counts to calculate the age-standardized rate and confidence intervals. However, the overall count of events contributing to the age-standardized rate is rounded when presented. For the special circumstance where the rounded overall count of events contributing to the age-standardized rate is zero, the actual age-standardized rate and corresponding confidence intervals are suppressed to maintain the ambiguity of zeros.

Further details on the CCR disclosure rules are available upon request via Health Statistics Branch Client Services (613-951-1746, or hd-ds@statcan.gc.ca).

Revisions and seasonal adjustment

This methodology type does not apply to this statistical program.

Data accuracy

Completeness

Since each Canadian province and territory has a legislated responsibility for cancer collection and control, case ascertainment of malignant tumours is considered relatively good. Each PTCR identifies tumours in its population by combining information from sources such as: cancer clinic files, radiotherapy and hæmatology reports; records from in-patient hospital stays, out-patient clinics, and private hospitals; pathology and other laboratory/autopsy reports; radiology and screening program reports; reports from physicians in private practice; medical billing and hospital discharge administrative databases; and, reports on cancer deaths from Vital Statistics registrars. Some PTCRs experience problems in submitting data to StatCan on a timely basis to update the CCR to reflect the current content of their registry. Cancer incidence data is currently not available for Quebec for diagnosis years 2018 onward and for Nova Scotia for diagnosis years 2020 onward.

As the CCR is a dynamic database, annual data collection includes new records for the current submission year as well as updates or new records from previously collected data years. As a result, the incidence for any given diagnosis year may change from one release to the next. In particular, delays in the reporting of new cases to StatCan typically result in undercounts of cases which are more pronounced in the most recently reported diagnosis year. Generally, the reporting delay ranges between 2% and 3% nationally. The missing cases are added to their appropriate diagnosis year, regardless of the year in which they are reported to the CCR.

In October 2014, Ontario implemented a new cancer reporting system, the Ontario Cancer Registry. The new system has several enhancements that permit the identification of cancer cases that previously went unrecorded. These include the use of more liberal rules for counting multiple primary sites, the use of additional source records and the inclusion of records that were previously not included. The implementation of this new system affects data from the 2010 diagnosis year onward.

Between 2011 and 2013, the Quebec Cancer Registry modified the sources used to quantify the number of new cancer cases, which impacted data from the 2011 diagnosis year onward. Before 2011, underestimates are observed and are more pronounced for prostate cancer, bladder cancer and melanoma. Years 2011 and 2012 are considered transition years, therefore, interpretation of data must be undertaken with caution.

Duplicates

To reduce the number of duplicate cases, a national duplicate resolution process was completed which included cases diagnosed up to December 31st, 2021 for all provinces and territories except Quebec and Nova Scotia. The de-duplication process was last completed for Quebec for all cases diagnosed up to December 31st, 2017. The de-duplication process was last completed for Nova Scotia for all cases diagnosed up to December 31st, 2019.

Under-reporting

Under-coverage of cancer tumours may exist for a variety of reasons: some PTCRs do not use, or have had periods in the past where they have not used, death certificates as a source of identifying cancer tumours; differing definitions among the PTCRs of what constitutes a reportable or malignant tumour; difficulty in diagnosing certain tumours because of their location (or site) in the body; differences among the PTCRs in coding practices, data entry or processing procedures; failure to report tumours diagnosed and treated in a province, territory or country outside of the province or territory of residence; and, delays in reporting of new cases to StatCan.

For the years 1992-2009 Ontario did not report in situ bladder cancers to the CCR; did not register non-melanoma skin cancers; and had underestimated cases of Kaposi's sarcoma.

In 2020 and 2021, the registration of new cancer cases in Canada may have been impacted by disruptions in screening and diagnostic services. Therefore, these data should be interpreted with caution.

Although the CCR strives to achieve national uniformity, reporting procedures and completeness vary across the country and differences may exist between the content of the CCR and the provincial/territorial cancer registries.

Death certificate only cases

Cancer incidence may be under-reported for a few Canadian provinces due to missing information on death certificate only (DCO) cases. A DCO case occurs when cancer is discovered through the cause of death information on a death certificate, as opposed to through a cancer report from the medical system. Ontario has not yet submitted DCO cases for diagnosis year 2021. Manitoba has not yet submitted DCO cases for diagnosis years 2013-2017, and 2021. Newfoundland and Labrador did not submit DCO cases until diagnosis year 2006. Nova Scotia has not yet submitted DCO cases for diagnosis year 2019.

Multiple primary cancers

For comparability, the annual release of cancer incidence disseminated by StatCan use the algorithm developed by the International Agency for Research on Cancer (IARC)* for determining multiple primary cancers.


*The International Agency for Research on Cancer (IARC) rules for determining multiple primary cancers (source: International Agency for Research on Cancer, International Association of Cancer Registries, and European Network of Cancer Registries. International Rules for Multiple Primary Cancers, (ICD-O Third Edition), Internal Report No.2004/02. Lyon, IARC, 2004).

Documentation

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