From about 1990, the number of people with early onset cancer has “increased dramatically” around the world.
Early onset cancers are those diagnosed before the age of 50 – and this upward trend, identified by US researchers in a new study, shows no sign of slowing.
Instead, the risk of early onset cancer is predicted to increase with each generation.
On the rise are cancers of the breast, colon, esophagus, kidney, liver, head and neck, prostate, bone marrow, and pancreas among others.
Scientists from Brigham and Women’s Hospital in Boston identified the lift in diagnosis numbers that began about 30 years ago – but the factors that led to cancer probably started years before in childhood..
What’s concerning is that the increase in early-onset cancers doesn’t seem to be slowing down – and improvements in screening alone don’t fully explain the trend.
“We found that this risk is increasing with each generation,” says one of the researchers, Shuji Ogino, a pathologist and epidemiologist at Brigham and Women’s Hospital in Boston.
“For instance, people born in 1960 experienced higher cancer risk before they turn 50 than people born in 1950 and we predict that this risk level will continue to climb in successive generations.”
Why is this happening?
The incidence of cancer has been on the rise in older people (those over 50) for about 80 years, and in recent years that increase has picked up in pace.
A 2021 investigation by a coalition of researchers, the Global Burden of Disease 2019 Cancer Collaboration, found that in 2010 there were 18.7 million people worldwide diagnosed with cancer.
In 2019, there were 23.6 million people diagnosed with cancer, leading the researchers to conclude “that the global burden of cancer is substantial and growing”.
Dr Shuji Ogino, is a professor and physician-scientist in the Department of Pathology at the Brigham, and co-author of the new study. He said:
“From our data, we observed something called the birth cohort effect. This effect shows that each successive group of people born at a later time (a decade later) have a higher risk of developing cancer later in life, likely due to risk factors they were exposed to at a young age.
“We found that this risk is increasing with each generation. For instance, people born in 1960 experienced higher cancer risk before they turn 50 than people born in 1950 and we predict that this risk level will continue to climb in successive generations.”
But why in people under 50?
While increased screening can explain some of these early-onset diagnoses, the increase was found to be apparent in countries without screening protocols or abundant resources.
The researchers said that “possible risk factors for early-onset cancer included alcohol consumption, sleep deprivation, smoking, obesity, and eating highly processed foods”.
Despite the common belief that adults are sleeping less hours, studies have found that adult sleep duration hasn’t drastically changed over several decades, although the question of sleep quality is under ongoing investigation.
However, the Brigham researchers report that “children are getting far less sleep today than they were decades ago”.
Which probably means those children are at added risk of developing cancer later in life, further fuelling the trends.
The researchers note that risk factors such as highly processed foods, sugary beverages, obesity, type 2 diabetes, sedentary lifestyle, and alcohol consumption have all significantly increased since the 1950s.
They speculate that this been accompanied by an altered microbiome.
“Among the 14 cancer types on the rise that we studied, eight were related to the digestive system. The food we eat feeds the micro-organisms in our gut,” said Dr Ugai.
“Diet directly affects microbiome composition and eventually these changes can influence disease risk and outcomes.”
In other words, as we’ve previously reported – see here and here – the poor quality food we eat for the sake of convenience, the hours we spend on the couch, and the booze we drink to offset our anxieties, are sending us to our graves.
