A report by the American Cancer Society showed that the incidence of colon and rectal cancer in younger people in the United States increased, with more cases recorded in the advanced stages of the disease.
According to the data of the report issued on Wednesday, one out of every 5 new cases infected with this disease occurs among people under the age of 55, which represents about double the rate in 1995.
In another worrying shift, the proportion of patients diagnosed with this type of advanced cancer rose to 60 percent from 52 percent between 2005 and 2010, according to the report.
The authors of the American Association report said that cases and death rates from colorectal cancer have continued to decline over decades, in general, thanks to better screening and treatments and reducing risk factors such as smoking, but new trends in the disease remain poorly understood, according to the Wall Street Journal.
Colorectal cancer is one of the most common types of cancer in the United States, and the second deadliest type of cancer after lung cancer.
About 153,000 cases are expected to be diagnosed in 2023, according to estimates by the American Society for Disease Control, including about 19,500 cases in people under the age of 50.
Colorectal cancer is most common among people between the ages of 65 and 74, but the incidence among people under the age of 50 is rising rapidly.
Oncologists remain unsure why rates are increasing among young adults, highlighting that changes in known risk factors including unhealthy diets, alcohol consumption and physical inactivity could contribute to this trend but do not fully explain the trend.
The American Cancer Society report recommends that people at greatest risk of colorectal cancer get regular screening at age 45.