Colon cancer is on the rise in young adults, according to a report published in the journal Science. Colorectal cancer diagnosed in individuals under the age of 50 is known as early-onset colorectal cancer (EOCRC). The most common symptoms include abdominal pain and rectal bleeding. Patients with EOCRC are often diagnosed with more advanced-stage disease and have worse survival rates compared to a later onset of the disease.

EOCRC has risen at a rate of 2 to 4 percent per year since the 1990s and is anticipated to become the leading cause of cancer death in those aged 20 to 49 by the year 2030. One in five colorectal cancer (CRC) cases diagnosed today is in people younger than 55, compared to one in 10 cases in 1995, according to the American Cancer Society.

The increased risk is carried through generations due to changes in environmental risk factors that disproportionately affect those born in recent decades compared to those born earlier. Obesity and other conditions related to metabolic syndrome, such as hypertension, hyperlipidemia, hyperglycemia and Type 2 diabetes are associated with CRC risk. Dietary factors, such as sugar-sweetened beverages, red and processed meat, and Western diets have also been implicated, as has the increased use of antibiotics, environmental toxins and higher rates of cesarean sections and other surgical procedures. Other possible reasons include genetics, low screening rates and misdiagnoses. Researchers also call for more research on the microbiome for EOCRC early detection and assessment.