First on CNN: Routine blood testing may hold hidden clues to colorectal cancer before age 45
First on CNN: Blood Tests May Flag Colorectal Cancer Clues
Qwenews.com – First on CNN, routine blood tests may offer researchers new clues about colorectal cancer diagnosed before age 45. An analysis from Epic Research found that younger adults with lower levels of two commonly measured liver enzymes, AST and ALT, were more often diagnosed with early-onset colorectal cancer than people with higher readings.
The findings do not show that low AST or ALT levels cause cancer. They also do not mean that someone should seek a colonoscopy solely because of one low blood-test result. The analysis identifies an association that needs further study, not a new screening rule for individual patients.
An Unexpected Signal in Standard Lab Work
AST, or aspartate transaminase, and ALT, or alanine transaminase, are often included in routine blood panels. Doctors generally pay closer attention to elevated levels, which can point to liver inflammation, injury, infection or disease. That made the connection between lower readings and early-onset colorectal cancer especially unexpected.
“The direction was a little counterintuitive. Clinically, we tend to watch for high liver enzymes, so seeing that low AST and ALT were associated with a higher likelihood of early-onset colorectal cancer stood out,” said Kersten Bartelt, a clinician and researcher at Epic Research who worked on the analysis.
Epic Research, owned by health-care software company Epic, released the analysis Wednesday. The work has not yet been published in a peer-reviewed journal, which is an important limitation. Researchers also reviewed triglycerides, cholesterol and potassium, but those measurements did not show an association with early-onset colorectal cancer.
What the Findings Could Mean for Younger Adults
First on CNN, the researchers emphasized that AST and ALT are not values people should attempt to raise. Low levels may reflect broader aspects of health, including muscle mass, nutritional status or frailty, rather than a direct biological cause of cancer.
“Our study shows the association but wasn’t built to uncover why,” Bartelt said. “Clinically, low AST and ALT can reflect things like lower muscle mass, frailty or nutritional factors. It’s one of the questions we hope this work prompts others to investigate.”
For patients, the practical message is to discuss laboratory results with a clinician who can consider symptoms, personal history and family history. A single number on a blood test rarely provides a complete assessment of someone’s health or cancer risk.
Colorectal cancer is now the leading cause of cancer deaths in the United States among people younger than 50. Researchers continue to examine family history, inherited genetics, obesity, metabolic health, diet, physical inactivity, the gut microbiome, antibiotic exposure and delayed recognition of symptoms. No single factor fully explains the increase in cases among younger adults.
Why More Research Is Needed
Because AST and ALT are widely available through standard blood testing, the finding could help researchers look for broader patterns in people who develop colorectal cancer at younger ages. It is not yet clear whether these measurements could eventually help identify people who might benefit from earlier evaluation or screening.
“Whenever there’s a focus on colon cancer, particularly early-onset colon cancer, we need to figure out why. There’s definitely been an increase in early-onset colon cancer, and if there are markers that point us towards the right patients to screen, that’s great,” said Dr. Marc Fenster, a gastroenterologist at Episcopal Health Services in New York who was not involved in the research.
FAQ: Colorectal Cancer and Routine Blood Tests in the US
Should a low AST or ALT result mean I need a colonoscopy?
No. This analysis does not establish low liver-enzyme readings as a reason by themselves to receive a colonoscopy. Speak with a health-care professional about your complete medical history, family history, symptoms and appropriate screening schedule.
What symptoms should younger adults discuss with a doctor?
Persistent changes in bowel habits, rectal bleeding, blood in stool, unexplained weight loss, ongoing abdominal pain or unusual fatigue should be discussed with a clinician. These symptoms can have many causes, but they should not be ignored.
Does this research change colorectal cancer screening recommendations?
No. First on CNN, the analysis was presented as an early research finding and has not yet been peer reviewed. Current screening decisions should continue to be guided by established recommendations and a clinician’s assessment of individual risk.