The number of people living with cancer is on the rise, according to a major new report from Statistics Canada.
Five-year cancer prevalence rates - which refers to the number of people who have been diagnosed with cancer in a given period and are alive on a specified date - rose for most types of cancer from Jan. 1, 1997 to Jan. 1, 2008.
The increase is due in large part to the aging population, improved detection of the disease through better screening, increases in underlying risk factors and improved survival rates for people who have been diagnosed.
It's the first time Statistics Canada has conducted a detailed report of cancer prevalence. Studying the prevalence rate of cancer is important because it allows for better understanding of changes in survival rates and incidence of cancer.
The five-year prevalence rate for all cancers at the beginning of 2008 was 1,490 for every 100,000 people. Prostate cancer had the highest prevalence rate at 610 cases per 100,000, while rates for thyroid, cervical, laryngeal and liver cancers were considerably lower at 53.1, 32.5, 10 and 6.2, respectively.
The five-year prevalence rate for all cancers rose 2.1 per cent per year from 1997 to 2008.
Aging was responsible for about half of the average annual increases in five-year cancer prevalence rates, according to Statistics Canada. For instance, prevalence of prostate cancer, one of the most common types of cancer, rose substantially in large part because the population is getting older.
But prevalence of the prostate cancer also rose among men younger than 70, which could be the result of more screening.
The annual increase in prevalence of breast cancer, the second most common type of the disease, rose higher before the beginning of 2001 than after. The average yearly increase in five-year prevalence rates was 1.3 per cent.
For certain cancers, such as liver, only 20 per cent of the increase in prevalence was due to aging.
The report also noted that annual increases in the prevalence of liver and thyroid cancer were more than double the increase for any other cancer.
Between men and women, prevalence rates of lung cancer were quite different. In men, prevalence rates declined about 0.3 per cent a year, while it rose in women about 3 per cent a year. The change is due to decreases in smoking among men since the 1960s, according to Statistics Canada.