More and more young people are being diagnosed with colorectal cancer. The increase is not small—the number of cases is up approximately 40 percent in the last 25 years. This is a stark contrast to the decrease of 40 percent in populations typically affected by the disease. Researchers at the University of Colorado Cancer Center want to know why more young people are being diagnosed and what can be done to reduce the burden in this population.
An Unsettling Trend
In 1990, only six percent of colorectal cancer patients were under 50 years old. That number has increased by about two percent each year.
“The incidence of colorectal cancer has increased by nearly 50 percent in young people,” says Dennis Ahnen, MD, gastroenterologist and CU Cancer Center member. “The reasons why this is happening are not clear. There are plenty of theories floating around that might explain the increase, but nothing is definitive.”
A rise in obesity among children and young adults, a decrease in childhood physical activity, increased consumption of processed meat, and changes in the microbiome due to antibiotic exposure are just some of the theories behind the rise of colorectal cancer in young people.
It is important to note that colorectal cancer is still predominantly diagnosed in individuals over 50 years old. However, there have been major movements to raise awareness of early onset colorectal cancer in the hopes of decreasing the numbers of misdiagnoses and later stage diagnoses.
The problem of NOT looking for a zebra
When medical professionals are trained, they are taught to think of the most common diagnoses first. The old adage goes, if you hear hoof beats, think of a horse, not a zebra. Medical professionals do not typically start looking for the “zebra” right away when a patient that is otherwise healthy presents with symptoms like blood in the stool or weight loss.
“Many symptoms of colorectal cancer can be explained by other medical conditions such as irritable bowel syndrome or hemorrhoids,” explains Christopher Lieu, MD, “Unless there are indicators that the person may be at a higher risk of developing the disease, more often than not doctors will not start looking for cancer right away.”
This can become problematic when someone does have cancer. According to a recent survey from the Colorectal Cancer Alliance:
- 82% of young cancer survivors were initially misdiagnosed
- 73% were diagnosed at a later stage
- 50% felt their symptoms were ignored
- 62% did not have a family history
- 67% saw at least two doctors before being diagnosed
“It is vital that the medical community becomes aware that more young people are being diagnosed,” says Ahnen. “When a patient comes in with symptoms like rectal bleeding, persistent abdominal discomfort, we need to consider that colorectal cancer could be what is causing the symptoms.”
Ahnen also recommends some adjustments in the way medical professionals screen patients. He recommends getting a thorough family history of cancer from younger patients. He also says it’s important to tell people with advanced adenomas (benign tumors in the colon) that their polyps were pre-cancerous. He also encourages those folks also to tell relatives so they know their whole family may be at higher risk for the disease.
Looking toward the future
Last month research leaders in the study of early-onset colorectal cancer met in a workshop organized by the patient empowerment group Fight Colorectal Cancer (Fight CRC), to set research priorities that could explain this increase. Andrea (Andi) Dwyer, at University of Colorado Cancer Center chaired and led this event based on her joint appointment with Fight CRC.
The conference, which hosted about 40 researchers from leading research institutions in the U.S. as well as international attendees from as far away as Spain, the Netherlands and the UK, and others joining remotely worldwide, identified several key steps in order to better understand early onset colorectal cancer. These include seeking funding for novel case control studies, collaborating with the National Cancer Institute (NCI) to inform policy and funding in this area, and working with the NCI and American Cancer Society (ACS) to identify future areas of research.