Incidence rates for non-metastatic prostate cancer (men aged ≥ 35)†, by province, by risk category, age-standardized to the 2011 population — 2012 diagnosis year
† Estimated using risk category data from 2012 diagnosis year and age-standardized incidence rates from 2010; see the Technical Appendix available at systemperformance.ca for more details.
A total of 93.9% of men had non-metastatic prostate cancer; 6.1% of cases were metastatic and were excluded from the analysis.
Data source: Provincial cancer agencies and Statistics Canada, Canadian Cancer Registry.
Data Table
Risk Category
Province
Cases
Risk Category (%), 2012 diagnosis yr
Age-Standardized Incidence Rate (overall), 2010 diagnosis yr
† Estimated using risk category data from 2012 diagnosis year and age-standardized incidence rates from 2010; see the Technical Appendix available at systemperformance.ca for more details.
A total of 93.9% of men had non-metastatic prostate cancer; 6.1% of cases were metastatic and were excluded from the analysis.
Data source: Provincial cancer agencies and Statistics Canada, Canadian Cancer Registry.
Figure 3.13
Distribution of non-metastatic prostate cancer cases (men aged ≥ 35), by risk category, by age group — 2012 diagnosis year
Data include: BC, AB, SK, MB, NB, NS, PE, NL.
Data source: Provincial cancer agencies.
Table 2.1
Criteria for which risk categories were assigned for non-metastatic prostate cancer cases based on the definition set out by Genitourinary Radiation Oncologists of Canada
This indicator examines the age-standardized incidence rates for non-metastatic prostate cancer by risk category (low, intermediate and high). The indicator also examines the distribution of prostate cancer risk profiles by age group. Only men aged 35 or older were included, as prostate cancer is extremely rare in men under age 35.
While stage is among the most useful tools for determining prostate cancer prognosis and treatment options, risk categorization systems are commonly used for evaluating patients with localized prostate cancer (i.e., whose cancers have not spread) as they 1) better clarify prognosis; and 2) can help guide decisions about treatment for patients with localized prostate cancer. The most commonly used risk categorization systems for prostate cancer are based on a combination of clinical-based pre-treatment prognostic factors: PSA value, biopsy Gleason score and Clinical T-Stage.
These three prognostic factors—which are rolled up into a more global risk category for each patient with localized prostate cancer—may help track and evaluate overall patterns of care (see the Patterns of Care indicator in Chapter 3: Treatment).
Risk categorization can predict how likely a specific cancer will respond to treatment and may help determine the risk for recurrence of disease after treatment.1
For this report, non-metastatic prostate cancer patients were categorized into three risk categories based on the Genitourinary Radiation Oncologists of Canada (GUROC) Canadian Consensus definition. Table 2.1 lists the prognostic characteristics within each risk category based on the GUROC guidelines.2 (Note: Not all prostate cancer cases were captured, due to incomplete data for one or more of the three prognostic factors used to calculate risk. See the Data and measurement considerations section for details.)
What are the results?
Figure 3.12 shows that most cancer patients were categorized as low- or intermediate-risk; but the data suggest substantial differences in the distribution of risk categories between provinces. Age-standardized incidence rates of low-risk prostate cancer ranged from 22.2 cases (British Columbia) to 124.6 cases (Prince Edward Island) per 100,000 men. For intermediate-risk prostate cancer, the incidence rates ranged from 57.8 cases (British Columbia) to 157.8 cases (New Brunswick) per 100,000 men. For high-risk prostate cancer, incidence rates were significantly lower, ranging from 44.5 cases (New Brunswick) to 88.5 cases (Manitoba) per 100,000 men. There was less interprovincial variation in the incidence of high-risk disease. One reason for this may be that variations in PSA testing patterns tend to reflect as differences in early stage prostate cancer incidence rates.
New Brunswick reported a high incidence of low- and intermediate-risk prostate cancers and a low incidence of high-risk cancers. Prince Edward Island and Newfoundland and Labrador reported the highest incidence rates of low-risk cancers but also reported some of the highest incidence rates of high-risk cancer (Figure 3.12).
Alberta, Saskatchewan and Manitoba reported relatively low incidence rates of low-risk prostate cancer and relatively high incidence rates of high-risk cancer (Figure 3.12). Further analysis is needed to link these patterns more definitively to differences in rates of PSA testing and other diagnostic investigations.
Overall, the proportion of localized prostate cancer patients who had higher-risk disease at diagnosis increased with increasing age at diagnosis. Most (72.0%) men over age 80 were classified as high-risk compared to a much smaller percentage (12.0%) of those in the 35-49 age group (Figure 3.13). It is important to note that prostate cancer is rare in younger men. (See Chapter 1: Burden and Outcomes for details on age-standardized incidence rates by age group.)
What do the results mean?
As of the 2010 diagnosis year, collaborative staging for prostate cancer cases had been implemented in nine of 10 provinces. Because collaborative staging includes more data points than the usual “tumour-node-metastasis” (TNM) anatomic-based staging system, the analysis of important prognostic factors such as PSA and Gleason score was enabled. Since these factors are used to determine appropriate treatment strategies at the patient level, population-level analysis can yield valuable information about overall treatment patterns and patient outcomes. For example, in Figure 3.13, the observation that older men are more likely to be categorized as high-risk may help plan cancer care services for these patients. (It is important to note that there was interprovincial variation in the completeness of data available to assign risk categories; as such, it is possible that patterns observed could reflect some data quality issues.)
The interprovincial variation in the incidence of prostate cancer by risk category could reflect differences in the use of PSA testing across jurisdictions. Those with a higher rate of PSA testing would be expected to have a higher incidence of low-risk prostate cancer. In order to reliably link risk category incidence patterns to differences in PSA testing rates across the country, we need reliable data on PSA testing rates for all provinces; these are not available (see Chapter 1: Burden and Outcomes for details on provincial variation in funding of and recommendations for PSA testing). Meanwhile, patterns of age-standardized prostate cancer incidence rates by risk category should continue to be monitored. This will help track whether more patients are being diagnosed as low-risk and whether this is accompanied by a decrease in mortality rates.
Older patients were more likely to be assigned a high-risk profile at diagnosis (Figure 3.13). These results are consistent with age-specific risk profiles in other jurisdictions, including the United States.3
References
D’Amico AV, Whittington R, Malkowicz SB, Schultz D, Blank K, Broderick GA, et al. Biochemical outcome after radical prostatectomy, external beam radiation therapy, or interstitial radiation therapy for clinically localized prostate cancer. JAMA. 1998 Sep 16;280(11):969-74.
Lukka H, Warde P, Pickles T, Morton G, Brundage M, Souhami L. Controversies in prostate cancer radiotherapy: consensus development. Can J Urol. 2001 Aug;8(4):1314-22.
Shao YH, Demissie K, Shih W, Mehta AR, Stein MN, Roberts CB, et al. Contemporary risk profile of prostate cancer in the United States. J Natl Cancer Inst. 2009 Sep 16;101(18):1280-3.
This indicator examines the age-standardized incidence rates for non-metastatic prostate cancer by risk category (low, intermediate and high). The indicator also examines the distribution of prostate cancer risk profiles by age group. Only men aged 35 or older were included, as prostate cancer is extremely rare in men under age 35.
While stage is among the most useful tools for determining prostate cancer prognosis and treatment options, risk categorization systems are commonly used for evaluating patients with localized prostate cancer (i.e., whose cancers have not spread) as they 1) better clarify prognosis; and 2) can help guide decisions about treatment for patients with localized prostate cancer. The most commonly used risk categorization systems for prostate cancer are based on a combination of clinical-based pre-treatment prognostic factors: PSA value, biopsy Gleason score and Clinical T-Stage.
These three prognostic factors—which are rolled up into a more global risk category for each patient with localized prostate cancer—may help track and evaluate overall patterns of care (see the Patterns of Care indicator in Chapter 3: Treatment).
Risk categorization can predict how likely a specific cancer will respond to treatment and may help determine the risk for recurrence of disease after treatment.528
For this report, non-metastatic prostate cancer patients were categorized into three risk categories based on the Genitourinary Radiation Oncologists of Canada (GUROC) Canadian Consensus definition. Table 2.1 lists the prognostic characteristics within each risk category based on the GUROC guidelines.529 (Note: Not all prostate cancer cases were captured, due to incomplete data for one or more of the three prognostic factors used to calculate risk. See the Data and measurement considerations section for details.)
What are the results?
Figure 3.12 shows that most cancer patients were categorized as low- or intermediate-risk; but the data suggest substantial differences in the distribution of risk categories between provinces. Age-standardized incidence rates of low-risk prostate cancer ranged from 22.2 cases (British Columbia) to 124.6 cases (Prince Edward Island) per 100,000 men. For intermediate-risk prostate cancer, the incidence rates ranged from 57.8 cases (British Columbia) to 157.8 cases (New Brunswick) per 100,000 men. For high-risk prostate cancer, incidence rates were significantly low¬-er, ranging from 44.5 cases (New Brunswick) to 88.5 cases (Manitoba) per 100,000 men. There was less interprovincial variation in the incidence of high-risk disease. One reason for this may be that variations in PSA testing patterns tend to reflect as differences in early stage prostate cancer incidence rates.
New Brunswick reported a high incidence of low- and intermediate-risk prostate cancers and a low incidence of high-risk cancers. Prince Edward Island and Newfoundland and Labrador reported the highest incidence rates of low-risk cancers but also reported some of the highest incidence rates of high-risk cancer (Figure 3.12).
Alberta, Saskatchewan and Manitoba reported relatively low incidence rates of low-risk prostate cancer and relatively high incidence rates of high-risk cancer (Figure 3.12). Further analysis is needed to link these patterns more definitively to differences in rates of PSA testing and other diagnostic investigations.
Overall, the proportion of localized prostate cancer patients who had higher-risk disease at diagnosis increased with increasing age at diagnosis. Most (72.0%) men over age 80 were classified as high-risk compared to a much smaller percentage (12.0%) of those in the 35-49 age group (Figure 3.13). It is important to note that prostate cancer is rare in younger men. (See Chapter 1: Burden and Outcomes for details on age-standardized incidence rates by age group.)
What do the results mean?
As of the 2010 diagnosis year, collaborative staging for prostate cancer cases had been implemented in nine of 10 provinces. Because collaborative staging includes more data points than the usual “tumour-node-metastasis” (TNM) anatomic-based staging system, the analysis of important prognostic factors such as PSA and Gleason score was enabled. Since these factors are used to determine appropriate treatment strategies at the patient level, population-level analysis can yield valuable information about overall treatment patterns and patient outcomes. For example, in Figure 3.13, the observation that older men are more likely to be categorized as high-risk may help plan cancer care services for these patients. (It is important to note that there was interprovincial variation in the completeness of data available to assign risk categories; as such, it is possible that patterns observed could reflect some data quality issues.)
The interprovincial variation in the incidence of prostate cancer by risk category could reflect differences in the use of PSA testing across jurisdictions. Those with a higher rate of PSA testing would be expected to have a higher incidence of low-risk prostate cancer. In order to reliably link risk category incidence patterns to differences in PSA testing rates across the country, we need reliable data on PSA testing rates for all provinces; these are not available (see Chapter 1: Burden and Outcomes for details on provincial variation in funding of and recommendations for PSA testing). Meanwhile, patterns of age-standardized prostate cancer incidence rates by risk category should continue to be monitored. This will help track whether more patients are being diagnosed as low-risk and whether this is accompanied by a decrease in mortality rates.
Older patients were more likely to be assigned a high-risk profile at diagnosis (Figure 3.13). These results are consistent with age-specific risk profiles in other jurisdictions, including the United States.532
Stage-specific incidence rates for prostate cancer (men aged ≥ 35), by province, age-standardized to the 2011 population — 2010 diagnosis year
PSA Testing
Percentage of men (aged ≥ 35) reporting at least one PSA test† in the past one year, two years or ever, by province/territory – 2010-2013 reporting years combined
Stage Distribution
Distribution of cases by stage at diagnosis for prostate cancer – 2013 diagnosis year
Prostate Cancer
Incidence rates for prostate cancer, by stage at diagnosis and province, age-standardized to the 2011 Canadian population — 2011–13 diagnosis years combined
