In recent years, a concerning trend has emerged in oncology: colorectal cancer is increasingly being diagnosed in people under the age of 50. This shift has prompted urgent research into the underlying causes, with experts pointing to lifestyle and environmental factors as potential contributors. Among them, Dr. Elena Élez, an oncologist at Vall d’Hebron Hospital and researcher at the Vall d’Hebron Institute of Oncology (VHIO) in Barcelona, has highlighted the possible role of pesticide exposure in the rise of early-onset colorectal cancer.
Speaking at a colloquium organized by CaixaResearch in February 2025, Dr. Élez emphasized that even as improved detection plays a part in the rising numbers, there is a genuine increase in risk linked to modifiable factors. She noted that unhealthy diets, physical inactivity, and exposure to certain environmental agents—including some pesticides—may be contributing to the disease’s earlier onset. These comments were reported by several Spanish media outlets, including La Vanguardia and Segre.com, which covered the event where she discussed the growing burden of colorectal cancer in younger populations.
Colorectal cancer remains a major public health challenge globally. According to projections from the Spanish Society of Medical Oncology, it was expected to be the most commonly diagnosed cancer in Spain in 2025, with over 44,000 new cases. It ranks as the second leading cause of cancer death in the country, with nearly 12,000 annual fatalities, most of which result from metastases rather than the primary tumor. The disease affects both men and women significantly, standing as the second most common cancer in each group after prostate and breast cancer, respectively.
The rise in early-onset cases is not unique to Spain. Similar patterns have been observed in countries undergoing Westernization, such as the United States and New Zealand, where studies have documented a steady increase in colorectal cancer diagnoses among adults under 50 over the past decade. This trend has intensified scrutiny on the so-called “exposome”—the cumulative measure of environmental exposures an individual encounters over a lifetime—and how it may interact with genetic and epigenetic factors to influence cancer development.
Research into the exposome’s role in early-onset colorectal cancer is ongoing. A study conducted by scientists in Spain, referenced in reports from VHIO and covered by medical news outlets, explored epigenetic markers linked to environmental exposures in young patients compared to those diagnosed later in life. While the study did not name specific pesticides, it aimed to identify biological signatures of exposure that could help explain the disease’s emergence in younger cohorts. Such research underscores the importance of understanding how external factors may leave molecular traces that contribute to carcinogenesis.
Experts continue to stress that prevention and early detection are critical. Public health initiatives promoting balanced diets rich in fiber, regular physical activity, and reduced intake of processed and red meats remain foundational. There is growing support for lowering the recommended starting age for colorectal cancer screening in certain high-risk populations, although guidelines vary by country. In the United States, for example, the U.S. Preventive Services Task Force recommends screening begin at age 45 for average-risk individuals, a change implemented in recent years in response to rising early-onset cases.
As research progresses, scientists are calling for more comprehensive studies that integrate environmental monitoring, biomonitoring of pollutants, and long-term health tracking to clarify the links between exposures like pesticides and cancer risk. Until such evidence is more definitive, health professionals advise minimizing unnecessary contact with agrochemicals, particularly in occupational or residential settings where exposure may be chronic, and advocating for stronger regulatory oversight of agricultural practices.
For now, the message from clinicians like Dr. Élez is clear: while age remains a significant risk factor, the evolving epidemiology of colorectal cancer demands attention to the world we live in and the substances we encounter daily. Ongoing investigation into the exposome offers hope for uncovering preventable causes and ultimately reducing the burden of this disease on younger generations.
To stay informed about developments in colorectal cancer research and prevention guidelines, readers are encouraged to consult authoritative sources such as the World Health Organization, the American Cancer Society, and national health agencies. Share your thoughts and experiences in the comments below, and help spread awareness by sharing this article with others who may benefit from this information.