Ontario Cancer Statistics 2022 Ch 3: Estimated Future Cancer Prevalence
Cancer prevalence is a measure of the number of people diagnosed with cancer who are alive. This chapter presents projected statistics on the prevalence of cancer in Ontario up to 2034. The projected statistics do not account for the effects of the COVID-19 pandemic.
What's on this page
Prevalent cancer cases include people who were recently diagnosed with cancer and are still under treatment, as well as people who are survivors of the disease. Survivors – defined in this report as people who are 2 or more years past their cancer diagnosis – make up the majority of prevalent cases in these statistics.
Cancer prevalence in Ontario has been rising due to a combination of improved cancer survival, lower mortality from the disease and increasing cancer incidence. Cancer incidence has risen as a result of improved early cancer detection and demographic changes in Ontario’s population, such as increasing life expectancy, and the growth and aging of the population.
Factors Affecting Future Prevalence
Demographic changes
In 2018, about half of all prevalent cancers were among people ages 60 to 79 (see Chapter 7: Cancer Prevalence). The advancing age of the baby boomer generation – people born from 1946 to 1964 and who make up the majority of the 60 to 79 age group – is expected to contribute to the growing incidence of cancer in Ontario. People age 65 and older will represent a larger proportion of cancer cases by 2034 compared with 2018. The greater proportion of seniors and population growth in the coming years are consistent with Ontario’s population projections.[1]
Improving cancer survival
Because cancer survival has improved over time for most cancers (see Chapter 6: Cancer Survival), the risk of cancer survivors developing a late effect of treatment or a subsequent cancer has grown. The proportion of subsequent primary cancers has steadily increased, with about 20% of new cancer cases in 2018 representing a second or subsequent new cancer diagnosis (Figure 3.2). Because multiple cancer diagnoses can have a compounding impact on quality of life [2], knowing the increasing proportion of subsequent cancers can inform the needs around care for future cancer survivors.
Prevalence projections for planning healthcare and social service
While statistics on recent cancer prevalence can be useful for understanding how many people with cancer are currently in different phases of cancer care (see Chapter 7: Cancer Prevalence), estimating the future prevalence of cancer can help health system planners, policy-makers and healthcare service providers anticipate the amount and type of health system resources needed to treat people recently diagnosed with cancer and provide follow-up services to cancer survivors. For example, prevalence projections can help ensure there is adequate distribution of health and social services to meet the future needs of survivors.[3]
In addition to helping predict future resources for treatment and recovery, other jurisdictions have shown that prevalence projections can be analyzed with other data and used by governments to plan for the costs associated with care and other services. Due to the growing cancer prevalence in the United States, cancer care costs were projected to increase 27% from 2010 to 2020.[4] Costs for care will depend on the proportion of people in different phases of survivorship and is expected to be highest in people recently diagnosed with cancer. However, the number of survivors who were diagnosed less than 5 years ago was projected to increase less than the number of cancer survivors who were diagnosed 5 or more years ago. Survivors who were diagnosed 5 or more years ago require supports that fall outside the cancer system and the costs associated with their care can be difficult to determine.[5] Finally, prevalence projections can influence research on the issues that survivors face, such as effects on quality of life, financial hardship and other social challenges.[6]
This chapter presents complete prevalence projections from 2019 to 2034 for all cancers combined and for the current 10 most prevalent cancers in Ontario. “Complete” cancer prevalence describes the number of people alive on a certain date (e.g., at the start of a calendar year) who were ever diagnosed with cancer. Complete prevalence therefore represents a heterogeneous group made up of people who were diagnosed many years ago (and are who likely to be cured of their cancer) and people who were diagnosed only recently (and who may still be undergoing cancer treatment).
Due to differences in methodology, statistics in this chapter and Chapter 7: Cancer Prevalence are not comparable.
Projected Trend in Prevalence
The prevalence of cancer is projected to increase from 2019 to 2034, from an estimated 845,188 people in 2019 to 1,265,216 in 2034 (Figure 3.3). Over this period, the prevalence proportion will have increased from 5,266.8 per 100,000 in 2018 to 5,612.5 per 100,000 in 2034. As in 2019, there is expected to be considerable heterogeneity in the prevalent cancer population in 2034 in terms of cancer type and how long people have survived beyond their cancer diagnosis.
The number of prevalent cases among males is expected to increase 45%, from 386,404 in 2019 to 558,836 by 2034. In females, the number of prevalent cases is expected to grow 54%, from 458,784 in 2019 to 706,380 in 2034 (Figure 3.4).
While the projected prevalence proportion is expected to continue to increase in females, the projected rate will decrease in males. The increasing prevalence proportion in females will be driven largely by a few cancer types (see next section, Projected prevalence by cancer type).
Projected Prevalence by Cancer Type
Table 3.1 shows that the change in prevalence over time is projected to differ by cancer type. In males and females combined, the prevalence proportion are expected to stay the same between 2019 and 2034. However, large relative increases in the prevalence proportion are expected for thyroid and kidney cancers. In males, the largest relative increases are similarly expected for thyroid and kidney cancers, while in females the greatest increases are expected for uterus and thyroid cancers.
The relative increase from 2019 to 2034 in the prevalence proportion of lung cancer is expected to be higher in females than in males.
| Cancer type | Both sexes Prevalence count (2019) |
Both sexes Prevalence count (2034) |
Both sexes Prevalence proportion (2019) |
Both sexes Prevalence proportion (2034) |
Males Prevalence count (2019) |
Males Prevalence count (2034) |
Males Prevalence proportion (2019) |
Males Prevalence proportion (2034) |
Females Prevalence count (2019) |
Females Prevalence count (2034) |
Females Prevalence proportion (2019) |
Females Prevalence proportion (2034) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| All cancers | 845,188 | 1,265,216 | 5,266.8 | 5,612.5 | 386,404 | 558,836 | 5,154.1 | 5,082.6 | 458,784 | 706,380 | 5,462.0 | 6,157.8 |
| Breast (female) | n/a | n/a | n/a | n/a | n/a | n/a | n/a | n/a | 164,674 | 236,420 | 1,937.8 | 2,013.4 |
| Colorectal | 77,097 | 115,460 | 470.6 | 503.6 | 42,225 | 64,386 | 564.6 | 599.3 | 34,872 | 51,074 | 394.0 | 421.6 |
| Kidney | 25,453 | 46,693 | 159.0 | 212.5 | 15550 | 30,531 | 206.9 | 296.5 | 9903 | 16,162 | 117.1 | 137.7 |
| Leukemia | 26,695 | 39,975 | 170.5 | 186.1 | 15,292 | 23,088 | 206.3 | 225.5 | 11,403 | 16,887 | 139.5 | 151.1 |
| Lung | 35,003 | 49,303 | 210.4 | 192.8 | 15,267 | 18,538 | 202.1 | 158.1 | 19,736 | 30,765 | 220.5 | 223.3 |
| Melanoma | 47,935 | 71,513 | 303.9 | 320.1 | 23,204 | 35,617 | 312.0 | 330.1 | 24,731 | 35,896 | 302.0 | 315.9 |
| Non-Hodgkin lymphoma | 41,901 | 67,949 | 262.9 | 301.4 | 22,686 | 36,772 | 304.8 | 349.1 | 19,215 | 31,177 | 226.4 | 259.3 |
| Prostate | n/a | n/a | n/a | n/a | 119,093 | 190,241 | 1,560.1 | 1,579.8 | n/a | n/a | n/a | n/a |
| Thyroid | 50,917 | 118,172 | 342.2 | 623.8 | 10,754 | 26,747 | 148.0 | 289.5 | 40,163 | 91,425 | 526.6 | 937.2 |
| Uterus | n/a | n/a | n/a | n/a | n/a | n/a | n/a | n/a | 33,822 | 60,849 | 389.4 | 516.6 |
Abbreviation: n/a means not applicable.
Notes:
- Prevalence counts are based on incidence counts using International Agency for Research on Cancer/International Association of Cancer Registries rules for counting multiple primaries.
- Prevalence proportions are per 100,000 and standardized to the age distribution of the 2011 Canadian Standard population.
Analysis by: Surveillance, Ontario Health (Cancer Care Ontario)
Data source: Ontario Cancer Registry (March 2021), Ontario Health (Cancer Care Ontario)
Projected Prevalence by Age
The anticipated growth in prevalent cases will vary by age group, with the relative proportion of cases increasing most for people age 60 and older (Figure 3.5).
Ages 0 to 39:
- In 2019, this age group represented about 4% of prevalent cases. In 2034, they will represent 3% of cases.
- The number of prevalent cases will increase slightly in this age group, with cases increasing 8%, from 37,222 in 2019 to 40,227 in 2034.
Ages 40 to 59:
- In 2019, this age group represented 21% of prevalent cases. In 2034, they will represent about 15% of cases.
- Similar to the youngest age group, a modest increase of 5% will occur among people ages 40 to 59 from 176,393 prevalent cases in 2019 to 185,269 prevalent cases in 2034.
Ages 60 to 79:
- In 2019, this age group represented about 55% of prevalent cases. In 2034, they will represent 56% of cases.
- Unlike younger ages, the proportion of prevalent cases will increase substantially in this age group, with cases increasing 52%, from 463,854 in 2019 to 705,601 in 2034.
Ages 80 and older:
- In 2019, this age group represented about 20% of prevalent cases. In 2034, they will represent 26% of cases.
- The change in the number of prevalent cases will be highest for people age 80 and older, with prevalent cases nearly doubling from 167,719 cases in 2019 to 334,119 cases in 2034.
Interpreting Prevalence Projections with Caution
Prevalence projections can be challenging to derive and interpret because they are a function of 2 other types of data: cancer incidence and survival. Therefore, the projections are sensitive to assumptions made about trends in incidence and trends in survival. For example, although historical incidence data are used to derive future incidence for calculating future prevalence, those data do not account for possible changes in recent practices that could affect the incidence of cancer such as early detection or cancer screening.
The prevalence projections also depend on the accuracy of the forecasts about population size. The approach used in this chapter assumes dynamic projections of the population.
Finally, several statistical methods exist for projecting prevalence, each relying on different types of available data. As a result, projected estimates can differ according to the method and the look-back period used.[7] The analysis presented in this chapter used the Prevalence and Incidence Analysis Model [8] (see Analysis for details), which has been used in many other jurisdictions.
Conclusion
The anticipated growth in cancer prevalence in Ontario is similar to findings from other modelling studies in the United States [5] and in the United Kingdom [9]. Because many cancer survivors are expected to live long after their diagnosis, it is important to consider the impact of cancer and its treatment, recurrence and subsequent cancers, psychosocial care and other important effects that survivors may experience.[6]
The projected statistics presented in this chapter can be useful for health system planners, health providers and social service providers when planning for the unique healthcare needs and challenges of the growing number of people living with and after recovering from cancer.