More than 1.5 million Canadians have been diagnosed with cancer in the last 25 years and were still alive in January 2018, according to a new report on the prevalence of cancer published by the Canadian Cancer Society (CCS).
Among Canadians with cancer, there were nearly 1.7 million cancer cases, as a person can receive more than one cancer diagnosis. Nearly half of all cancer cases involved breast, prostate, or colorectal cancers. Other common diagnoses included skin cancer, thyroid cancer, bladder cancer, Hodgkin’s lymphoma, uterine cancer, and lung cancer.
Cancer prevalence is the number of people who are diagnosed with cancer and then survive. The report says cancer outcomes have generally improved in recent decades, even though cancer prevalence in Canada has increased from 10 years ago.
In other words, people with cancer are diagnosed earlier and survive longer. But, the trend is also a growing number of Canadians diagnosed with cancer than in the past. In 2012, according to the report, approximately 193,000 people in Canada were diagnosed with cancer. By 2017, that number had grown to 206,000.
cancer on the rise
The CCS estimates that 233,900 people will be diagnosed with cancer in 2022. This increase in incidence is attributed to the growth and aging of Canada’s population. Older Canadians are more likely to be diagnosed with cancer, according to the report.
As of January 1, 2018, nearly 18,000 children under the age of 15 had been diagnosed with cancer in the previous 25-year period studied. One in four had received a cancer diagnosis in the last five years and 10 percent had been diagnosed in the previous two years.
Among childhood cancer diagnoses, leukemia was responsible for 35 percent of diagnosed cancers. The report said: “Most childhood cancer survivors are at increased lifetime risk of being diagnosed with a second primary malignancy. This increased risk may be due to genetic predispositions or certain adverse effects induced by treatment toxicity.”
However, the report was not all bad news. He noted that survival outcomes for children with cancer are expected to increase in the future, especially for cancers that affect the blood and bone marrow.
COVID data not considered
The report only used data for a 25-year period, through January 1, 2018. The data in the report does not take into account any changes in cancer diagnosis, control, and prevalence due to COVID-19. However, the report notes that international data suggests that 40 percent fewer cancer diagnoses were made between March 9 and May 17, 2020, compared to the average number of cancer diagnoses made in the same period. time period in 2018 and 2019.
Additionally, according to the CSS, there is some early data from provincial figures that suggest cancer surgeries were down in number during the first four months of COVID-19.
A September 2022 report, “Living at the crossroads of COVID-19 and cancer”, he said the pandemic has led to delays and disruptions in medical care, which could result in more late-stage diagnoses. Finding the cancer later means a lower survival rate, according to the CSS.
At the regional level, there are also disparities. The incidence of cancer per 100,000 people in the past 25 years was generally higher in the eastern provinces and lower in the western provinces. Cancer prevalence was higher in rural Canada than in urban areas, and the report attributes the higher cancer numbers in rural areas to their typically larger populations compared to the city.
The CCS report also noted that established cancer risk factors, such as smoking, alcohol use, and obesity, are more common risk factors in people living in rural areas, contributing to a higher incidence of cancer. cancer. Also, travel from rural areas to larger health care facilities can be more difficult for people who live in the countryside.
Little chance of surviving lung cancer
The report noted that the incidence rate of colorectal cancer is lower than that of lung cancer, but lung cancer has a relatively poor survival prognosis. “For both breast and prostate cancer, about two-thirds of cases were five to 25 years from diagnosis, while 15 percent of each were still within the first two years from diagnosis. . In contrast, for lung cancer, only 37 percent were more than five years from their diagnosis.
There are also differences in how cancer affects the sexes, defined by the report as “those assigned male and female at birth.”
Cancer of the bladder, kidney and renal pelvis, head and neck, stomach, liver, and esophagus are three times more common in men. Thyroid cancers in women are three times more common than in men.
The report says that “these observed sex differences in prevalence may reflect differences in genetic factors and risk factor distributions for these cancers, as well as differences in patterns of diagnosis and referral.”
Nearly half of all 25-year-old prevalent cancers among men were due to prostate and colorectal cancers. The age group most affected by commonly diagnosed cancers was highest in the 70-79 age group. For women, breast cancer was highest in the 60-69 age group.
“Breast cancer was the most common 25-year prevalent cancer in all geographic regions except Newfoundland and Labrador, New Brunswick, and Prince Edward Island, where prostate cancer was most common,” the report said.
Health Care Strain
Income also played a role in the cancer statistics, but it varied by type of cancer. Higher-income neighborhoods reported higher levels of breast and prostate cancer. Low-income Canadians had a higher prevalence of colorectal and lung cancer, and people in these low-income groups were less likely to survive.
In the Press release Accompanying the study, Jennifer Gillis, Senior Surveillance Manager at CCS, said: “Increasing prevalence – more people diagnosed and more survivors – creates long-term strain on our health care system and underscores why we must work together to create a system that can evolve. as patient needs evolve from diagnosis to survival to end-of-life care.”
Analysis of statistics related to the continuing rise in new cancer cases diagnosed annually, as well as the number of people surviving beyond their cancer diagnoses, is intended to help governments properly plan and prepare for emergency resources. necessary medical care. For example, a recent study estimated that the costs of cancer care rose from $2.9 billion per year in 2005 to $7.5 billion in 2012. The CSS said that a simulation-based study estimated that the direct cost of cancer in the health care system medical in 2021 could have reached $22.8 billion.