Is that why so many young people get colon cancer? Doctors say a fungus could be to blame
Doctors may be one step closer to understanding why colorectal cancer cases are soaring in younger adults.
A mysterious rise in cases among those under 55 has sparked concern in medical circles, particularly as the cancer occurs in healthy youth who “run marathons” and watch their diet.
Now doctors at Georgetown University in Washington DC say the surge could be linked to changes in young people’s gut microbiome.
They found that tumors in younger patients were more likely to contain the fungus Cladosporium sp. contained. compared to older patients.
The fungus is only occasionally found in the human gut, where it is believed to be an invader that does not aid in digestion. The fungus is also known to cause skin and nail infections.
Scientists Are One Step Closer to Understanding Why Colorectal Cancer Cases are Rising in Young People (stock)
According to the National Cancer Institute, colon cancer is the third most common cancer in the United States. And it’s increasing in young people.
Approximately 153,000 Americans are diagnosed with colon cancer each year, of which 19,550 are under the age of 50.
Rates among the under-55s have doubled since the 1990s, raising concerns among health professionals.
For example, a 2023 report by the American Cancer Society says the rate of colon cancer in Americans under age 55 has increased from 11 percent of all cases in 1995 to 20 percent in 2019.
dr Benjamin Weinberg, an expert on gastrointestinal cancer, told AXIOS, “A lot of people blame obesity and diabetes.”
“But we have these patients who run marathons and eat.” [healthy diets] and they have very advanced colon cancer.”
For the study, scientists examined tissue samples from 63 patients aged under 45 or over 65 years.
They examined the DNA of the microorganisms in the tumors to look for differences in the gut microbiome.
This revealed that Cladosporium sp. was more common in tumors in young patients than in older patients.
The researchers also assessed bacterial factors that might play a role.
There was no difference for most bacteria, such as Fusobacterium nucleatum, which was found about 30 percent of the time in both groups.
Other bacteria were also found to be more common in the tumors of older patients.
It is still unclear how Cladosporium sp. could be driving this increase in cases, but researchers think it could damage cell DNA. This could cause them to turn into cancer cells.
The results are scheduled to be presented next week at the American Society of Clinical Oncology annual meeting in Chicago, Illinois.
The researchers say their work may have brought doctors a step closer to understanding what’s causing the rise in colorectal cancer cases.
dr Weinberger added, “We assume there was some kind of exposure in the 1970s or 1980s — maybe everyone started taking antibiotics for ear infections, or they stopped breastfeeding.”
“Something happened where this cohort is seeing this increase and we don’t know why.”
Previous theories suggest that unhealthy diets, alcohol consumption and the increase in sedentary lifestyles could be responsible for the rise.
But scientists say that doesn’t explain why other cancers have remained stable or continued to decline at the same time in the under-55s.
Tumors can contain bacteria as well as fungi, although these are not usually present.
Part of the increase may be because people are more likely to be diagnosed at a later stage when colorectal cancer is more difficult to treat.
A 2017 study in the journal Clinical Gastroenterology and Hepatology found that people under 50 tended to wait two months longer to see a doctor after first noticing symptoms than people over 50.
In 2021, amid concerns about the rising rate among younger adults, the US Preventive Services Taskforce lowered the screening age from 50 to 45.