Cancer outpaces cardiovascular disease as biggest middle-aged killer in rich nations
Cancer has outpaced cardiovascular disease as the main killer of middle-aged people in high-income countries, while the latter still kills more worldwide in general, a new study finds.
In the first global study of its kind, researchers in Canada studied more than 162,500 adults between age 35 and 70 from 21 countries, following them for a median of 9.5 years, according to a statement. The research was published in The Lancet on Tuesday and presented at the European Society of Cardiology Congress.
It stems from the ongoing Prospective Urban Rural Epidemiology (PURE) study led by the Population Health Research Institute (PHRI) of McMaster University and Hamilton Health Sciences in Hamilton, Canada.
Study subjects were age 50 on average when the study started in 2005, BBC News outlined. More than 11,000 died between the start and 2016. People in low-income countries were four times more likely to die than in high-income countries, BBC News reported.
“The fact that cancer deaths are now twice as frequent as cardiovascular disease deaths in high-income countries indicates a transition in the predominant causes of death in middle age,” said Salim Yusuf, principal investigator of the study, executive director of PHRI and a professor of medicine at McMaster, in a statement.
With advances in the prevention and treatment of cardiovascular disease, cancer is set to outpace that cause globally in coming years, Yusuf said.
He noted that poorer countries do not have more cancer risk factors than people in higher-income nations. But they may have less access to quality health care.
“As cardiovascular disease declines in many countries because of prevention and treatment, cancer mortality will likely become the leading cause of death globally in the future,” he said. “The high mortality in poorer countries is not due to a higher burden of risk factors, but likely other factors including lower quality and less health care.”
Canada, Saudi Arabia, Sweden and United Arab Emirates were the high-income countries studied, with Argentina, Brazil, Chile, China, Columbia, Iran, Malaysia, Palestine, Philippines, Poland, Turkey and South Africa in the middle-income category. Lower-income countries were Bangladesh, India, Pakistan, Tanzania and Zimbabwe.
Worldwide, cardiovascular disease continued to be the most common cause of death, with 40% of middle-age deaths attributable to it, the researchers found. However, there was a marked difference when the countries it occurred in were factored in. Just 23% of middle-aged deaths stemmed from heart disease in high-income countries, while for middle- and low-income countries it was 41% and 43%, respectively.
That held even though cardiovascular risk factors were highest in the high-income countries and lowest in low-income countries, the researchers found. Likewise, cancer accounted worldwide for 26% of middle-age deaths, but the breakdown was 55% in high-income countries, 30% in middle-income nations and just 15% in low-income countries.
The study also revealed that non-communicable diseases accounted for a larger proportion of deaths and hospitalizations in higher-income nations than infectious diseases did. It also showed that poorer countries had fewer cardiovascular disease risk factors but a higher rate of death from those conditions.
Lastly, the findings suggested that “lower-quality health care may be responsible, at least in part, for the higher mortality in poorer countries,” the researchers’ statement said.
“The implications are that in higher-income countries, while continued efforts to prevent and treat cardiovascular disease should continue, new efforts to reduce cancer are required,” said Darryl Leong, the co-lead author of the study, a scientist at the Population Health Research Institute and an assistant professor of medicine at McMaster University.
“The world is witnessing a new epidemiologic transition among the different categories of non-communicable diseases, with cardiovascular disease no longer the leading cause of death in high-income countries,” said Dr. Gilles Dagenais, Emeritus Professor at Laval University, Quebec, Canada and lead author of the cancer report, in a statement. “Our report found cancer to be the second most common cause of death globally in 2017, accounting for 26% of all deaths. But as cardiovascular rates continue to fall, cancer could likely become the leading cause of death worldwide, within just a few decades.”
The study results mirrored what has been emerging in the U.S., too, in a study last year in the Annals of Internal Medicine, reported CNN.
“We are seeing a new epidemiologic transition – from heart disease to cancer as the leading cause of death – which is occurring first in high-income communities,” Dr. Latha Palaniappan, lead author of last year’s study and a professor of medicine at Stanford University Medical Center in California, told CNN.
She called it a unique opportunity to understand what reduced heart disease incidence in high-income countries and use that knowledge to help lower-income populations.