As the risk of colon cancer rises for young people across the world, two new studies were released just this week about the condition. So, why are young people are getting it more frequently?
“That is the million-dollar question that a lot of scientists and researchers are working to try and answer, said Dr. Kimmie Ng, founding director of the Young-Onset Colorectal Cancer Center at the Dana-Farber Cancer Institute, in a recent interview with The Excerpt podcast.
She said that experts believe the increase is linked to an environmental factor, since colon and rectal cancers are already known to be linked to environmental factors. According to Ng, the surge in cases among people age 50 and younger is a global phenomenon.
While she said “individuals in the Black population are 20% more likely to be diagnosed with colorectal cancer and at a younger age when they're diagnosed and 40% more likely to die,” this new spike is steepest among non-Hispanic whites, as well as people who live in more “westernized” environments.
In the U.S., there has been a rise in young onset colorectal cancer in all 50 states. Increased rates also appear to be linked to a “birth cohort effect,” which typically means that an environmental factor is contributing to disease incidence among a group born within a specific timeframe.
“The statistics show that a person who was born in 1990 compared to a person of the same age who was born in 1949 now has quadrupled the risk of developing rectal cancer and over double the risk of developing colon cancer,” Ng explained.
Dana Taylor, host of The Excerpt, also said that breastfeeding has been linked with a 23% increased risk of developing colorectal cancer. Ng said that the link is not yet well understood and that mothers should not feel discouraged from breastfeeding, as it has many benefits as well.
Still, she said that more aggressive action should be taken to address rising colorectal cancer risks. Within the next six years, colon rectal cancer among Americans 20 to 34 years old is expected to increase by 90%. Rectal cancer rates expected to increase by 124%.
Although the age for recommended screenings was recently lowered to 45 years, Ng said this likely isn’t enough to help mitigate the growing risks.
“When we look at the statistics, the rates of rise are actually steepest among people in their 20s and 30s,” she said. “And even with this new guideline change, they still are not eligible for screening, and that is a concern.”
Ng said that more research into what causes these cancers should help efforts.
New research published Wednesday in the European Journal of Human Genetics focused on the cause of hereditary colorectal cancer. Another study published Tuesday in the Scientific Reports journal was about genes that could predict the prognosis of colorectal cancer.
However, Ng noted that many young patients with colorectal cancers have no family history of cancer or genetic conditions. In fact, many are healthy, and while obesity has been floated as a potential risk factor, Ng said most young patients she sees with the conditions are not obese.
“We’ve also looked at risk factors like sedentary behavior, drinking sugar sweetened beverages, low levels of vitamin D, and they’ve all been reported to be linked,” she said. “But again, it probably will come down to not just one environmental factor. We’re also really trying hard to understand whether the biology of these tumors is different when they happen in a younger person compared to an older person.”
For people who are concerned about having or developing the cancer, Ng said symptoms to look out for include blood in stool and pelvic discomfort.
“If you have any change in bowel habits, more frequent diarrhea or constipation doesn’t mean you have colon cancer, but it’s something to be alert for,” said Medical Editor Dr. Brian McDonough of Audacy station KYW in a recent interview. “It could be a sign something’s going on. We get a little more concerned when you have rectal bleeding or blood in the stool. Yes, it could be a hemorrhoid or something, but it could also be a sign that something’s going on internally.”
Audacy stations KNX and WCBS have also reported on research into a blood test that could make screening for colorectal cancers easier.
“There were previous blood tests, but they had very poor sensitivity and specificity, so they weren't recommended very well,” explained Dr. John Carethers, a gastroenterologist and vice chancellor for Health Sciences at UC San Diego. “This particular blood test examines, what we call cell free DNA. This is leakage of DNA that could come from a cancer into the bloodstream, very microscopic amounts, and be detected by a blood test.”
Dr. David E. Rivadeneira, director of Northwell Health Cancer Institute at Huntington noted that the test had not yet been approved by the U.S. Food and Drug Administration as of this March.
“I think certainly in time, as several other studies mature, I think it will probably be FDA approved, maybe late in the year or next year, he told WCBS.
Currently, 80% of our patients with young onset colorectal cancer have children under the age of 18 when they’re diagnosed and many are also caring for elderly parents according to Ng. As these diagnoses put families under strain, there are some lifestyle habits people can try to in attempt to mitigate their risk.
“The more natural, the better,” said KYW’s McDonough. “The less processed, the better. So that means, you know, fruits and vegetables and salads and whole wheat. All of those things are good and they’re helpful."