Colorectal cancer increasing in younger population, according to The Lancet

12 December 2024

Colorectal cancer incidence is increasing among younger adults below 50 years in high-income western countries in contrast with the older population, a study published in The Lancet Oncology says.

The study investigates colorectal cancer incidence trends in younger adults versus older adults. The generational shift found in colorectal cancer risk points at environmental and lifestyle factors that affect early life and young adulthood in post-baby boomer generations. These factors include diets, lack of physical activity, and obesity.

Based on previous scientific work, the group of researchers from the US and France found that the rise in early-onset colorectal cancer is no longer confined to high-income western countries; it now extends to diverse economies and countries in eastern Europe, Asia, and Latin America and the Caribbean.

Japan and Chile are two examples of this. Having achieved notable economic advancement decades ahead of many of its regional counterparts, Japan has seen the steepest rise in early-onset colorectal cancer in Asia. A considerable shift from traditional diets, rich in low-fat and high-fibre foods, to increased consumption of red or processed meat, sugars, and ultra-processed convenience foods has probably contributed, at least in part, according to the study.

Similarly, Chile, which has sustained steady economic growth over last decades and outperformed neighbouring countries has shown the fastest increase in early-onset colorectal cancer in Latin America and the Caribbean. Previous studies cited in this article link the rising incidence of colorectal cancer in Latin American countries to the economic liberalisation and globalisation of food systems in the late 1980s to early 1990s.