Iana dos Reis Nunes was 43 when she told her husband that she could feel something like a bubble in her abdomen when she lay on her side.
An ultrasound scan found spots on her liver, which led to blood tests and a colonoscopy.
“There was a tumor the size of your fist, and she had no pain and no problems with bowel movements or anything like that,” recalled Brendan Higgins, her husband, who works as an artist in New York City.
By the time doctors found it, dos Reis Nunes’ colon cancer had spread. It was stage 4, meaning it had reached other parts of her body.
The family was blindsided.
“She had had a baby 15 months prior to her diagnosis, so she’d had a million blood tests, you know, care from doctors and sonograms … and there was no indication of anything, nothing whatsoever.”
When cancer strikes an adult under the age of 50, doctors call it an early-onset case. These cancers at younger ages are becoming more common.
A new review of cancer registry records from 44 countries found that the incidence of early-onset cancers is rising rapidly for colorectal and 13 other types of cancers, many of which affect the digestive system, and this increase is happening across many middle- and high-income nations.
The review’s authors say the upswing in younger adults in happening in part because of more sensitive testing for some cancer types, such as thyroid cancer. But testing doesn’t completely account for the trend, says co-author Shuji Ogino, a professor of pathology at the Harvard T.H. Chan School of Public Health.
Ogino says the spike is due to an unhealthy stew of risk factors that are probably working together, some which are known and others that need to be investigated.
He notes that many of these risks have established links to cancer like obesity, inactivity, diabetes, alcohol, smoking, environmental pollution and Western diets high in red meat and added sugars, not to mention shift work and lack of sleep.
“And there are many unknown risk factors as well, like a pollutant or like food additives. Nobody knows,” he said.
Ogino thinks the fact that so many of these cancers – eight out of 14 studied – involve the digestive system points to a big role for diet and the bacteria that live in our gut, called the microbiome.
“I think this actually is an important piece because what it’s pointing to is changing exposure prevalences at early ages, that are producing earlier-onset cancers,” says Dr. Elizabeth Platz, an epidemiologist at the Johns Hopkins Bloomberg School of Public Health who also edits the journal Cancer Epidemiology, Biomarkers & Prevention, who was not involved in the review.
Take obesity. Once, it was rare. Not only has it become more common to have a dangerously high body mass index, but people are becoming obese earlier in life, even in childhood, so these cancer risks are building decades earlier than they did for previous generations.
An explosion of colorectal cancer in younger adults
The surge in early-onset colorectal cancer – the cancer dos Reis Nunes had – has been particularly steep.