Study: Trends in the prevalence of cancer

Warning View the most recent version.

Archived Content

Information identified as archived is provided for reference, research or recordkeeping purposes. It is not subject to the Government of Canada Web Standards and has not been altered or updated since it was archived. Please "contact us" to request a format other than those available.

Related subjects

    [an error occurred while processing this directive]
1997 to 2008

Five-year cancer prevalence rates for most cancers increased from January 1, 1997, to January 1, 2008. Increases were relatively large for liver and thyroid cancer, while rates declined for cancers of the larynx and cervix. The biggest disparity between the sexes was for cancer of the lung, for which rates declined slightly among men, but continued to increase among women.

For all cancers combined, the five-year prevalence rate at the beginning of 2008 was 1,490 cases per 100,000 population. The most prevalent was prostate cancer (610 cases per 100,000). In comparison, the corresponding prevalence rates for thyroid (53.1), cervical (32.5), laryngeal (10.0) and liver cancer (6.2), were considerably lower.

In general, cancer care services required within the first five years after diagnosis include primary treatment and supportive care, followed by close clinical assessment for recurrence.

Several factors may lead to increases in prevalence rates, including the aging of the population, improved detection of disease through advancements in screening, more extensive use of screening, increases in underlying risk factors for disease and improved rates of survival for people with cancer.

For all cancers combined, roughly half of the reported average annual rates of increase for five-year prevalence were attributable to aging. However, for individual cancers, the role of aging varied considerably. For example, about 20% of the increase in prevalence for liver cancer was a result of aging.

Rates of change

The five-year prevalence rate for all cancers combined rose 2.1% per year from 1997 to 2008.

The average annual increases in five-year prevalence rates for liver and thyroid cancer were more than double the increase for any other cancer.

The five-year liver cancer prevalence rate increased 8.3% per year. For thyroid cancer, the average annual increase was 7.9%: 3.7% from 1997 to the beginning of 2000, and 9.5% from 2000 to 2008. Increases were higher in men for liver cancer, but higher in women for thyroid cancer.

Note to readers

This study is the first detailed report of trends in cancer prevalence in Canada. "Prevalence" is used here to refer to all cancers diagnosed within a given period among people alive on a specified date. It should not be confused with "incidence," which refers to newly occurring cases.

Five-year prevalence at the beginning of 2008 was estimated by counting the number of cancers diagnosed from January 1, 2003, to December 31, 2007, among people alive at the beginning of 2008.

Changes in cancer prevalence rates result from changes in the incidence of and survival from the disease. Several factors, the importance of which varies by cancer type, may account for changes in incidence and survival.

Prevalence was calculated using cancer incidence data from the January 2011 version of the Canadian Cancer Registry (CCR), a population-based database maintained by Statistics Canada. The CCR contains information on cases diagnosed from 1992 onward, compiled from reports from every provincial and territorial cancer registry.

Mortality data, also used in prevalence calculations, come from the Canadian Vital Statistics Death Database, also maintained by Statistics Canada. Data on deaths are based on information provided by the vital statistics registrars in each province and territory.

For data comparability reasons, the analysis excludes data from Quebec.

Among the cancers considered in this study, declines in prevalence rates occurred only for cancers of the larynx and cervix. For example, the annual average rate of decrease in five-year prevalence for laryngeal cancer was 1.9% and for cervical cancer, 1.5%.

Leading cancers

Prevalence rates for prostate cancer, the most common cancer in Canada, rose substantially, primarily because of the aging of the population over the study period. For example, the five-year prevalence rate for this cancer increased 3.0% per year from 1997 to 2008.

Substantial increases in prostate cancer prevalence rates occurred among men in all age groups younger than 70 years. Average annual rate increases were highest at ages 40 to 49. The size of the increase fell in each successively older age group.

Increases in the prevalence of breast cancer, the second most common cancer and the most common in women, were more moderate. The annual rate of increase in five-year breast cancer prevalence was about three times higher before the beginning of 2001 (+2.3%) than afterward (+0.7%). Over the entire period, the five-year prevalence rate rose by an average of 1.3% per year.

Colorectal and lung cancer were the third and fourth most common cancers, respectively. The average increase in five-year colorectal cancer prevalence from 1997 to 2008 was 2.3% per year: 2.5% per year to the beginning of 2003 and 1.9% per year afterward. Increases for colorectal cancer were highest for people aged 20 to 39.

For lung cancer, the five-year prevalence rate increased 2.6% per year since the beginning of 2005, up from a rate of less than 1% a year before this period. Over the whole period, the rate increased by an average of 1.3% per year.

Between the sexes, changes in the prevalence rate of lung cancer diverged. In men, the rate declined slightly, 0.3% per year, but in women it increased 3.0% per year. This discrepancy was the result of sharper decreases in smoking prevalence among men since the mid-1960s.

Definitions, data sources and methods: survey numbers, including related surveys, 3207 and 3233.

The article, "Canadian trends in cancer prevalence," part of Health Reports, Vol. 23, no. 1 (82-003-X, free), is now available from the Key resource module of our website under Publications. For more information on this article, contact Larry Ellison (613-951-5244;, Health Statistics Division, or Kathryn Wilkins (613-951-1769;, Health Analysis Division.

Also released today is "Adopting leisure-time physical activity after diagnosis of a vascular condition." The majority of Canadians aged 40 and older are inactive in their leisure time. They tend to remain inactive after being diagnosed with a condition such as high blood pressure, heart disease or diabetes. For more information on this article, contact Pamela L. Ramage-Morin (613-951-1760; or Julie Bernier (613-951-4556;, Health Analysis Division.

For information about Health Reports, contact Janice Felman (613-951-6446;, Health Analysis Division.

For information about the Canadian Health Measures Survey, 2007 to 2009, or to enquire about the concepts, methods or data quality of this release, contact Statistics Canada's Media Relations (613-951-4636).