Over the past 30 years, early-onset cancer rose 79 percent, one global study found

(Rachel Uda) —  When Catherine, Princess of Wales, revealed that she was diagnosed with cancer, it stunned the world.

She’s active, she apparently maintains a diet rich in antioxidants and raw fruits and veggies, and she’s only 42. But sadly, the princess is part of an alarming global trend. Studies show that more and more young people seem to be developing cancer. We’re taking a closer look at the latest research on young-onset cancer.

Studies show cancer is striking more young adults

A 2023 study found that over the past three decades, cases of early-onset cancer — defined as those appearing in people under age 50 — shot up a striking 79 percent, while death among younger cancer patients rose 28 percent.

The paper, published in BMJ Oncology, analyzed data from 204 countries and found that breast cancer accounted for the largest number of these, while windpipe and prostate cancers rose the fastest among younger patients over the 30-year period.

Another study focusing on U.S. patients found a modest bump in under-50 cases, but a substantial increase in people diagnosed between the ages of 30 and 39. Cancers among this group, from 2010 to 2019, rose about 19 percent. In line with the global analysis, breast cancer was found to be the most common among younger patients, while the fastest-growing cancers were gastrointestinal.

What’s causing the rise in cancer rates in young adults?

Researchers don’t know exactly. Experts have long pointed to alcohol, tobacco use, and poor sleep as factors. The rise in obesity and environmental factors like pollutants and toxic chemicals we may encounter in our water and food could play a role too.

Some of it simply has to do with the fact that more people are getting screened and diagnosed earlier, says Katherine Crew, M.D., an oncologist and associate professor of medicine and epidemiology at Columbia University Medical Center.

“We’re offering more patients genetic testing, and when they test positive, are screening those people at a younger age. Women with BRCA-1 or BRCA-2 mutations might start breast MRI screening in their mid-20s or patients with Lynch syndrome might start colonoscopies earlier too,” Dr. Crew tells us. “I think that’s part of what’s driving this.”

Another area of focus has been the gut microbiome, the trillions of bacteria, viruses, and fungi living in your intestinal tract. The composition of this universe of microorganisms can be easily thrown out of whack by antibiotics or diets heavy in processed foods, which has been linked to inflammation and certain cancers.

The chances that there’s a “smoking gun,” or one factor that’s behind this disturbing trend is unlikely, says Peter Liang, M.D., a gastroenterologist and assistant professor at NYU.

“It’s much more likely that it’s a combination of different factors that play a role,” Dr. Liang tells us.

That’s why researchers like him, who are trying to get to the bottom of the rise in early-onset cases, are looking at an impressive array of possible culprits. Surveys from Dr. Liang’s study, called the Colorectal Cancer in Adults at Young Onset (CRAYON), ask participants questions like what kinds of jobs they had as teenagers to determine if they could have been exposed to any toxins, if they were breastfed, and even if they were born by C-section. (One recent study found that women born by cesarean were more likely to develop CRC before 50.)

“We have to do more right now and we need answers to be able to figure out how to protect future generations,” he says.