The number of cancer cases and deaths in Canada is expected to increase this year because of a growing and aging population. But despite this trend, the overall incidence rates of people diagnosed with and dying from cancer will continue to decline, according to the latest data from the Canadian Medical Association Journal (CMAJ).
The study, published Monday, projects there will be 247,100 new cancer diagnoses and 88,100 cancer deaths in 2024. This is up from an estimated 239,100 cancer cases and 86,700 cancer deaths in 2023.
“Cancer has a major impact on the people and the economy of Canada. These estimates highlight where progress has been made to reduce those impacts, and where more attention and resources are needed,” lead author Dr. Darren Brenner, an epidemiologist and associate professor at the Cumming School of Medicine, University of Calgary, said in a Monday media release.
Cancer is the number one cause of death in Canada, according to 2021 data from Statistics Canada. An estimated two in five Canadians will be diagnosed with cancer in their lifetime and about one in four will die from cancer.
The CMAJ study, a collaborative effort between the Canadian Cancer Society, Statistics Canada and the Public Health Agency of Canada (PHAC), said it aims to provide estimates for the number and rate of new cancer cases and deaths in 2024 for 23 cancer types by province or territory and sex.
To do this, it looked at national data on cancer cases between 1984 and 2019 and deaths from cancer between 1984 and 2020.
“Having an understanding of what the current burden of cancer in Canada is really important for policymakers and programs to have a better idea of how to plan and allocate resources,” explained Ioana Nicolau, senior epidemiologist of the Canadian Cancer Society surveillance team.
“It also gives us an idea of what efforts are needed to be made in terms of uptake of screening and what risk factors all of us really should be aware of,” she told Global News.
Cancer cases, deaths in Canada
As the population grows and ages, new cancer cases and deaths from the disease in Canada are increasing, the authors say.
Lung cancer is projected to be the most diagnosed cancer, with 32,100 new cases, and remains the leading cause of cancer death for both males and females in 2024, the study said. This is followed by breast, prostate and colorectal cancers.
The top four cancers (lung, breast, prostate and colorectal) are expected to make up almost half (47 per cent) of all new cases in 2024.
However, when adjusting for Canada’s aging population, overall incidence and mortality rates are projected to decrease slightly from previous years for both males and females. The study added that this is projected to continue to decrease for some of the most common cancers, including lung, colorectal and prostate.
The authors argue these declines are likely due to continued efforts across the cancer control spectrum and improvements in prevention, screening and treatment.
For example, lung cancer rates in Canada have been steadily decreasing over the years, despite it being the most common type of cancer. According to the Canadian Cancer Society, the most significant reason lung cancer death rates are improving is due to a reduction in commercial tobacco use, which is the leading risk factor for the disease.
“As for colorectal cancer rates, there has been the biggest decrease of all other cancers. And this is due to the organized, collective screening programs,” Nicolau said.
However, the study found that incidence rates of cancers that are less common, including liver and intrahepatic bile duct cancer, kidney cancer, melanoma and non-Hodgkin lymphoma, are projected to increase.
Increases in the incidence of liver and intrahepatic bile duct cancers have been tied to factors such as alcohol consumption, hepatitis B and C infection, obesity and diabetes, the study said. Kidney cancer has emerged as one of the cancers most strongly associated with excess body size, diabetes and high blood pressure.
“One cancer in particular that’s concerning is melanoma cancer because it’s highly preventable. And we’re continuing to see an increase in the incidence rates for both males and females. So again, just noticing that it’s important for all of us to know the risk factors and practice sun safety every year-round,” Nicolau said.
What regions in Canada will be most impacted?
The study revealed that cancer mortality rates are notably higher in eastern Canada when compared to their counterparts in the west.
While the study didn’t delve into the reasons behind this regional variation in cancer rates, Nicolau suggested that there could be various reasons contributing to this discrepancy.
“There are differences in the risk factors across the country. There are also differences in screening practices and screening uptake and also differences in cancer diagnoses,” she said. “So, it really could be many different factors of why we’re seeing that variation across the country.”
For example, in Canada, the current breast cancer screening guideline set by the Canadian Task Force on Preventive Health Care (CTFPHC) is age 50, but accessibility differs by province.
A publicly-funded mammogram is available to Prince Edward Island women annually, between the ages of 40 and 74. But in Manitoba, routine breast screening is recommended for women over the age of 50. In Ontario, screening is available starting at age 40.
Last week, the Canadian Cancer Society urged all provinces and territories to begin breast cancer screening at age 40 for those at average risk of the disease.
What can be done?
In a related editorial link published Monday, Dr. Keerat Grewal, a clinician scientist at the Schwartz/Reisman Emergency Medicine Institute at Sinai Health, Toronto, and Dr. Catherine Varner, deputy editor at the CMAJ, argued that receiving a cancer diagnosis in an emergency department is becoming routine in Canada.
“Which highlights the failure of health-care systems to support adequate primary care–initiated pathways for diagnosis of suspected cancer. One in 5 people in Canada do not have a regular primary care provider and, even among those who do, many report poor access to primary care,” the editorial read.
The authors of the CMAJ study conclude that access to outpatient clinics should be expanded to streamline suspected cancer diagnosis, such as Ontario’s diagnostic assessment program clinics.
They also recommended more guidance to support patients discharged from the hospital emergency room.
“It’s important at the health systems level to focus efforts on prevention in terms of screening,” Nicolau said.
“So really focus on increasing screening participation. And I think that would make a huge impact down the road.”