||As of this Report |
|Reporting of cancer stage at diagnosis.
|See Methodology and Approach to find out how the ratings are calculated. |
For patients diagnosed in 2013, Ontario achieved approximately 68% stage capture rate for all cancers. This represents a decrease of 3% from 2012 (71%), and it is well below the Cancer Care Ontario (CCO) aim of 90%. Please note that this does not mean that patients are not being staged prior to treatment by their clinicians. It means that the stage capture rate reflects the ability to enter the data into the stage capture system in the cancer registry only.
Population-based stage capture (also known as collaborative stage) rates in Ontario now reflect the impact of the new, more liberal case counting rules implemented in the Ontario Cancer Registry and starting with cases with a diagnosis in 2010. This now aligns Ontario with other Canadian provinces and the United States. The change in these rules for Ontario, however, effectively increased the total number of cases available to be staged, although this does not represent an increased incidence of cancer from a clinical perspective.
Reliable stage capture information is essential to ensure that CCO can track how many cancer patients are diagnosed in the early (stage I) versus late (stage IV) stage of cancer; this in turn allows CCO to look for trends at the population level and based on current performance. More work is required to ensure documentation of the stage of all cancers.
What is cancer staging?
- Staging describes the extent or severity of a person’s cancer, based on the size and/or extension of the original (primary) tumour and how far it has spread in the body1.
- Almost all cancer patients begin their involvement with the cancer system through a series of diagnostic tests. These likely include imaging and, in some cases, removal of tissue or cells from the body for examination (biopsy) so that the nature and extent of the cancer can be determined.
- Stage values for invasive cancer range from stage I, which means the disease is in the early phase, to stage IV, which means the cancer has spread (or metastasized) to other organs or places in the body. An unknown stage is the result of either limited stage work-up and/or limited documentation within the patient record.
- Knowing the stage of the disease helps physicians plan appropriate treatment and determine the likely outcome or course of the disease.
- Population-based staging data (staging for all newly diagnosed cancer patients) is critically important information that is used in cancer system surveillance, planning and improvement3.
What is the collaborative staging data collection system?
- Collaborative staging (CS) is a standard method of collecting staging information using a minimum dataset of coded elements from a cancer pathology report, supplemented by clinical data found in diagnostic imaging reports, laboratory tests and physician summaries. The information can be used and shared electronically by agencies and organizations that study cancer data.
- The CS common dataset describes key cancer tumour characteristics and ensures cancer agencies around the world interpret and analyze the data the same way.
- Knowing cancer stage allows cancer agencies and hospitals to better evaluate the appropriateness and effectiveness of cancer treatments delivered throughout the province.
- CS in Ontario has grown. While it previously represented a subset of patients from outside Ontario’s Regional Cancer Centres (RCCs) (representing less than 15% stage capture in the first year of data collection), it has since expanded to include both RCCs and non-RCC hospitals, starting with the four most common cancers (breast, prostate, colorectal and lung). The use of CS expanded during 2010–2011 to include melanoma of the skin and gynecologic cancers. This was followed by a further expansion in 2013 to include thyroid cancer.
- RCCs continue to submit Tumor, Node, Metastases (TNM) stage data to CCO via Databook for those sites not being staged using CS. TNM is a system maintained collaboratively by the American Joint Committee on Cancer (AJCC) and the International Union for Cancer Control (UICC), with the most recent version being AJCC 7th Edition. The TNM system, like CS, classifies cancers by the size and extent of the primary tumor (T), involvement of regional lymph nodes (N) and the presence or absence of distant metastases (M). In recent years, this has been supplemented by nonanatomic prognostic factors. Unlike CS, TNM does not retain the raw data elements (e.g. the exact tumor size or number of lymph nodes involved), and it does not generate a combined stage based on both clinical and pathologic sources.
What do the results show?
Impact of the new Ontario Cancer Registry on CS capture rates:
- The new rules used by the Ontario Cancer Registry allow additional cases to be created based on key diagnostic attributes, such as laterality, subsite and timing between cancers. The number of stageable cases (effectively the denominator for this indicator) increases, which is why the percentage of staged cases appears to decrease for the years 2010–2012 when compared to previously published rates. It is very important to note that the actual incidence of cancer has not increased from a clinical perspective.
- The scope of the stage capture program at CCO currently includes the following cancers: breast, colon, appendix, rectosigmoid, rectum, lung, prostate, cervix, uterus, ovary, fallopian tube, vagina, vulva, placenta, melanoma of skin and thyroid. CCO’s aim is to ultimately stage all cancers in the registry.
- Population-based stage capture (i.e. CS) rates in Ontario for all cancers in the Registry now reflect the impact of the new, more liberal case counting rules implemented with the start of the new Ontario Cancer Registry (Figure 1). The new Registry creates cases based on the new rules starting with 2010 diagnoses, and these rules effectively increased the denominator or number of stageable cases, and lowered the stage capture rates for all years being reported.
- The total volume of stageable cases in Ontario increased by an average of 14% per year between 2010–2012 (Figure 1). This increase in case count is a direct result of the implementation of new case generation rules in the Ontario Cancer Registry, and it does not represent an increased incidence of cancer from a clinical perspective. (Note: the Ontario Cancer Registry Information System (OCRIS) volume of cases for 2013 was a projected volume and not an actual case count.)
- Staging for 2013 was not complete as of the CSQI February 2015 publication date: new cases created in the last quarter of 2014 were not yet staged and require additional resources to address. For the diagnosis year of 2013, Ontario achieved approximately 68% stage capture for all cancers, which is a decrease of 3% from 2012 (71%) (Figure 2).
- Collaborative staging attempts to stage all cases of a specific type (e.g. breast cancer) so that meaningful inferences about that cancer can be made at the provincial level. TNM staging from the cancer centres is meaningful to the individual cases and the reporting facilities, but it does not capture all cancers of a single type across the province (Figure 2). The stage capture rate continues to be below the CCO aim of 90% for all cancers, although the scope of the program has expanded from the initial four most common sites of breast, colorectal, lung and prostate to include gynecologic cancers, melanoma of the skin and thyroid cancer. In total, these sites represent 71% of all stageable cases in the registry over the time period 2010–2013 (Figure 3).
- Stage distribution was not included in the 2015 Cancer System Quality Index (CSQI) report as it is an indicator on rotation, but it will be analyzed in full for the 2016 CSQI report.
Why is staging information important to patient care?
Accurate cancer stage information can improve quality of care and decision-making in the cancer system.
- Determining the exact location, size and spread of the cancer (i.e. the stage) is essential for selecting the best treatment for the patient2.
- Linking the stage of cancer with outcome and treatment data provides valuable information, allowing the cancer system to assess the quality of cancer care and identify new ways to improve the delivery of that care. For example, this CSQI provides performance information on the following indicators (which depend on accurate stage information):
- The value of stage capture on a population basis not only includes the evaluation of successful screening programs, but also the pinpointing of priority areas where resources for treatment can be increased for specific diseases where the incidence of advanced cancers is high3. The information also is valuable for identifying high-risk groups for education and screening.
- For many patients who are going through the cancer diagnostic journey—from when cancer is suspected, to its diagnosis and determination of stage (or to it being ruled out)—can be a confusing and anxious time. To help transform the diagnostic phase of the cancer journey for patients, health-care providers and the health-care sector, CCO developed Diagnostic Assessment Programs (DAPs) across the province.
Collaborative staging leads to a more efficient system.Collaborative staging includes automated data capture from synoptic pathology reports, combined with the direct review of hospital patient records. This leads to more accurate collection of stage-related pathology information and increased efficiency within the cancer system. This results in fewer cases with unknown stage.
Find out moreFor more information on stage capture, go to CCO’s website. To listen to CCO’s webinar on the Ontario Cancer Registry changes, go to the Ontario Cancer Registry page on CCO's website.
- American Joint Committee on Cancer [Internet]. 2008. Adapted from “What is cancer staging?”; [cited 2015 February 11]. Available from: https://cancerstaging.org/references-tools/Pages/What-is-Cancer-Staging.aspx
- National Cancer Institute [Internet]. Date unknown. Purpose of staging; [cited 2010 April 12]. Available from: http://training.seer.cancer.gov/staging/intro/purpose.html.
- Brierley JD, Srigley JR, Yurcan M, Li B, Rahal R, Ross J, King MJ, Sherar M, Skinner R, Sawka C. 2013. The value of collecting population-based cancer stage data to support decision-making at organizational, regional and population levels. Healthcare Quarterly. 16(3): 27–33.