Mr. Speaker, the creation of uniform national standards and guidelines for the surveillance of all malignant and benign brain tumours has the potential to improve the quality and completeness of brain tumour registration across Canada.
Complete and accurate data on primary brain tumours will facilitate research into the causes of this disease, which may lead to improved diagnosis and treatment of patients. Currently, published statistics usually include malignant tumours only.
Benign tumours are slow growing and do not invade important structures, while malignant tumours are fast growing and may invade and damage important structures.
Nevertheless, for improved cancer surveillance, it is worthwhile for cancer registries to collect and report standardized information on benign brain tumours since they result in similar symptoms and outcomes as malignant tumours.
Ideally, data collection by cancer registries should include all tumours of the central nervous system.
Cancer registries have been created in each of the provinces and territories but the sources of data and relevant legislation varies.
In addition to provincial-territorial registries, a central Canadian cancer registry is maintained at Statistics Canada that includes selective data from each of the provincial and territorial registries.
Cancer registries serve several purposes by linking available resources of administrative data to obtain information on the number of new cancer cases and corresponding patient follow-up information. This information allows basic surveillance and establishes a platform to provide the additional information needed to develop and evaluate cancer control programs.
Current users of cancer registries include linkages to other administrative databases, such as vital statistics, to further assess potential causes of cancer, such as behavioural risk factors, as well as occupational and environmental exposures.
A total of 2,500 cases and 1,650 deaths from malignant brain and nervous system cancer are expected in 2006 in Canada. The number of brain and nervous system cases registered would be increased by around 40% to 70% if benign cases were included.
Based on the underlying cause reported on death certificates, the number of deaths would be increased by about 30% when benign and uncertain brain tumours are included. Benign cases contribute a substantial proportion of the total burden of brain cancer.
The inclusion of benign brain tumours in standard data collection and the adoption of standard site and histology definitions for tabulating benign brain tumours is needed to incorporate these tumours fully into the Canadian cancer registry and allow comparability of information across registries and internationally.
Including non-malignant brain tumours in the Canadian cancer registry is also needed to allow these tumours to be studied fully, including an evaluation of the trends and the rates of newly diagnosed cases for this type of cancer. It will be necessary to report and analyze data for non-malignant central nervous tumours separately from malignant tumours.
By including data on these two tumour types in the registries, it will be available for use in analytic epidemiology research studies that will help identify factors that influence the risk for developing malignant and non-malignant brain tumours.
Another reason why it is important to include benign brain tumours in registration is that there is a large number of sub-types of brain and nervous system cancer.
The chance of recovery prognosis and choice of treatment depend on the type, grade and location of the tumour and whether cancer cells remain after surgery and/or have spread to other parts of the brain. For example, survival rates are generally higher for benign meningiomas than for malignant meningiomas but the treatment of benign tumours may be limited by their location.
Favourably situated lesions are usually amenable to complete removal by surgery, while other types are more difficult to fully and safely excise.
Reporting of benign brain cancer is expected to increase the total overall number of reported cancer cases by about 1%. There would be some implications for registries to this added reporting, including some modest costs, the need for training and database upgrades and possibly revisions in legislation.
Registries may also need access to additional sources of administrative data to ensure that cases not included in current sources are captured. For example, when cases are not hospitalized shortly after diagnosis, access to other data sources, such as pathology records or physician claims data, becomes more important.
Completeness of reporting is critical for cancer registries. Accurate case counts are necessary to assess the burden of cancer, to guide cancer control program planning, to prioritize the allocation of health resources and to facilitate epidemiological research. This is a particular challenge for registries with access to limited sources of administrative data.
Cancer registry information is continually being enhanced with data relevant to these programs. For example, stage data: the extent of disease at the time of diagnosis was not collected when cancer registration was initiated.
However, currently there is a collaborative initiative between the cancer registries, Statistics Canada and the Public Health Agency of Canada to collect cancer stage data at the time of diagnosis. Stage information is necessary to better describe and evaluate cancer survival and cancer control programs. Other data enhancements are being considered to fill the information gap between diagnosis and death.
In addition to adding cancer stage data to the cancer registries, current priorities for enhanced cancer surveillance under exploration with provinces, territories and cancer stakeholders are the collection of radiation and other treatment data: treatment access, treatment outcome, improved record linkages and consideration of privacy legislation.
These ongoing enhancements of the cancer registries will also benefit the study of both benign and malignant brain tumours. For example, studies have demonstrated that some benign brain cancers transform to malignant tumours. To understand the factors that might contribute to this transformation and whether incidence rates for both malignant and non-malignant tumours are affected, the full spectrum of the disease needs to be included in cancer registries.
In the area of enhanced surveillance of cancer control interventions, it will take some time to see the impact, especially some of those that require primary prevention intervention relatively early in life. That creates a need for the registry to capture another class of indicators of potential success or process measures, that is a measure which is not sufficient in itself to prove the efficacy of the intervention, but one that is on the pathway to effective prevention, such as reduction in smoking prevalence or on the pathway to effective screening, such as reduction in the absolute prevalence of advanced cancer, or on the pathway to effective treatment, such as prolongation of disease free survival.
Knowing more about the risks for brain cancer and its evolution and impact across a lifetime is particularly important because brain cancer is a significant cancer among young adults. In 2003 there were 388 cases diagnosed within the 20 to 44 age group, or close to 20% of brain cancer cases among Canadians aged 20 or older.
Five years after diagnosis, 23% of patients diagnosed with malignant brain tumours during 1995 to 1997 were alive, compared to the expected survival of persons the same age in the Canadian population. Survival for benign tumours is better with a relative survival rate of 70% is to be expected.
Teams can be made up of physicians, neurosurgeons, nurses, pharmacists, radiation oncologists, neuro-oncologists, dietitians, therapists and/or social workers.
It is clear that for Canadian cancer registries to provide the most complete information for brain tumours, data on both benign and malignant tumours needs to be collected. I ask all hon. members to join me in commending the member for introducing the motion and to give it their full support.