Early-onset colorectal cancer on the rise in higher income countries

April 28, 2022 0 By CH Unnikrishnan

Early-onset colorectal cancer, defined as being diagnosed when younger than 50, continues to steadily increase in the US and other higher income countries, reveals the latest review by Mayo Clinic researchers. It is also important to note that most of these cases are without a known hereditary basis and have no identifiable cause, the review article stated.  

The cases at less than 50 years of age currently accounts for 10 percent of colorectal cancer cases, and the incidence is fast increasing, particularly in high-income countries. Patients often present with advanced disease in the left colon and one in six patients has deficient DNA mismatch repair. Therefore, screening is now recommended to begin at 45 years of age.

The rising cases among the young has also been established by several other ongoing researches involving large cohorts and international consortia that aim to identify early life exposures that are most relevant to the development of early-onset colorectal cancer.

“We are seeing a significant increase in the numbers of younger patients with colorectal cancer at Mayo Clinic, as is occurring around the country,” says Dr. Frank Sinicrope, an oncologist and gastroenterologist at Mayo Clinic Cancer Center in Minnesota, and an author of the study, published in The New England Journal of Medicine.

“Public health measures are needed to address risk factors for colorectal cancer, beginning in adolescence, including poor dietary habits and physical inactivity,” said Dr. Sinicrope, adding that while the specific causes of early onset colorectal cancer remain elusive, data suggest that diets with high intake of red and processed meat, as well as refined grains and processed sugar can alter gut microbial composition, resulting in chronic inflammation, increased rates of obesity and a higher risk of colorectal cancer. 

“Evidence suggests that a plant-based diet and more physical activity may help promote a more favourable gut microbiome, which in turn may reduce the risk of colorectal cancer,” Dr. Sinicrope suggested in a Mayo Clinic statement.