Obesity and colon cancer: a predicted pandemic among young adults

UPDATE DAY

The latest statistics confirm that colorectal cancer is striking earlier and will soon become the leading cause of cancer death in adults under 50.

Historically, colorectal cancer represented the prototype of a slowly growing cancer, requiring several decades to gradually acquire the many mutations required to evolve from the initial precancerous lesion (polyp) to a clinically detectable tumor, usually after age 65.< /p>

In recent years, however, there has been an unprecedented increase in the incidence of colorectal cancer in young adults under the age of 50, around 2 to 4% per year, this increase even reaching 8% annually. among those under 30. (1)  

Since our genes obviously have not changed in such a short time, the early onset of a cancer that normally takes decades to manifest necessarily implies that factors associated with modern lifestyle greatly accelerate the onset and development of these tumors.

Earlier and more aggressive

According to a recently published editorial in the prestigious journal Science, it is really urgent to look into this new trend if we want to avoid a real health catastrophe in the coming years. (2)

As the authors mention, not only does colorectal cancer declare itself earlier, but it also has a more aggressive character: early tumors have a distinct clinical presentation, with a predilection for the left side (the descending portion of the colon ), and affected patients are often diagnosed with a more advanced (metastatic) tumor. 

As a result, even though these patients are young and less affected by other health (comorbidities) than the older ones, they do not show superior survival despite the possibility of using more aggressive treatments. (3)

For all these reasons, specialists anticipate that early colorectal cancer could become the leading cause of cancer death in young adults aged 20-49 by 2030. (1)

Metabolic disorders

However, this situation is not irreversible since it has been clearly demonstrated that several risk factors associated with modern lifestyle are responsible for this increase in the incidence of early colorectal cancer. Pervasive obesity and associated metabolic disorders, a problem that has been on the rise in recent decades, clearly play a role.  

A large study of 85,256 women revealed that obesity in adolescence is associated with a significantly higher risk of early colorectal cancer in midlife. (4)

A negative impact of modern diets (sweetened beverages, red meats and deli meats), physical inactivity as well as various metabolic disorders (hypertension, hyperlipidemia, hyperglycemia, type 2 diabetes mellitus) has also been observed.  < /p>

Overall, therefore, the rise in the incidence of early colorectal cancer affecting young adults under 50 can be seen as another tangible (and dramatic) manifestation of the disastrous consequences of obesity that result from poor modern dietary habits. . Our individual and societal laxity in the face of overweight will have catastrophic consequences in the future, by disproportionately mobilizing medical resources that will no longer be available to treat other less prevalent health problems. The support of a health system has its limits which are already being exceeded and this tsunami of overweight is only in its infancy.

(1) Akimoto N et al. Rising incidence of early-onset colorectal cancer – a call to action. Nat. Rev. Clin. Oncol. 2021; 18: 230-243.

(2) Giannakis M and Ng K. A common cancer at an uncommon age. Science 2023; 379:1088-1090.

(3) Lipsyc-Sharf M et al. Survival in young-onset metastatic colorectal cancer: findings from Cancer and Leukemia Group B (Alliance)/SWOG 80405. J. Natl Cancer Inst. 2022; 114: 427-435.

(4) Liu PH et al. Association of obesity with risk of early-onset colorectal cancer among women. JAMA Oncol. 2019; 5:37-44.