Early-onset colorectal cancer progresses in the same way as average onset colorectal cancer. The corresponding study was published in the Journal of the National Cancer Institute.
Colorectal cancer is the third most commonly diagnosed cancer and the second leading cause of cancer deaths in the US. While it is most commonly diagnosed between the ages of 65 and 74, since the mid 1990’s, incidence rates of the disease occurring in those under 50 years old have increased between 1% and 2% per year.
In the current study, researchers compared the progression of early-onset and average-onset colorectal cancer using data from the Memorial Sloan Kettering Cancer Center collected between 2014 and 2019.
All in all, they had access to data from 759 patients who developed the disease before the age of 50- characterized as early-onset colorectal cancer- and 687 patients diagnosed with the disease aged 50 years or older- characterized as average-onset colorectal cancer. They compared the location of tumors, symptoms at diagnosis, risk for hereditary colorectal cancer, and other tumor molecular features.
Importantly, the researchers found the genetic makeup of the tumors in both groups of patients, and their responses to treatment at advanced stages, were indistinguishable. This, says the researchers, suggests that early-onset colorectal cancer is not biologically distinct from average-onset colorectal cancer. They also noted that more aggressive treatments for early-onset colorectal cancer were neither effective nor necessary.
The researchers did note some differences between the two onset times of the disease, however. They noted that those who develop the disease earlier were more likely to have tumors on the left side of the body, and were more likely to experience rectal bleeding, abdominal pain, and have a genetic predisposition for the disease.
“The study noted no specific findings to differentiate early-onset colorectal cancer patients from average-onset colorectal cancer patients,” said Cathy Eng of Vanderbilt-Ingram Cancer Center, who wrote an editorial to accompany the study.
“I am hopeful with increased awareness and education, other investigators will collect additional data inclusive of a diverse patient population to determine if the findings from this study apply to the general public impacted by early-onset colorectal cancer," she added.