Do you personally know someone too young to have cancer? I do.
I’m sure you do too and you’re not just imagining the growing trend. Unfortunately, the rising trend in young-onset cancer is real. Most cancers used to occur in older people but are becoming more and more common in the young. This trend has been particularly noticeable for colorectal cancer.
Colorectal cancer is a cancer of the large intestine (the colon or rectum). The rapid increase in young-onset colorectal cancer is alarming, especially because we have seen a great drop in the number of colorectal cancers in people over 50 since the 1990s– largely due to colonoscopy screening in people over 50.
For adults younger than age 50, the incidence of colorectal cancer has been steadily increasing by 1-2% per year. In fact, it is estimated that by the year 2030, about 11% of all colon cancers and 23% of all rectal cancers will occur among people younger than 50. In my personal practice as a colorectal surgeon, about half of my rectal cancer patients are under 50 years old. At first, I too thought I was imagining the trend, but then, more and more clinicians started speaking about it, and large organizations such as the American Cancer Society, National Cancer Institute, and American Society of Colon & Rectal Surgeons began to report this trend and allocate research dollars to help explain the problem and find a solution.

What is causing the alarming rise of colorectal cancer in the young?
Experts have not yet found one unifying cause for the rise. Certain genetic conditions like Lynch syndrome and familial adenomatous polyposis or inflammatory gut conditions such as ulcerative colitis predispose young patients to colorectal cancer. However, these represent a small minority of our patients.
We also know that factors such as obesity, physical inactivity, and smoking increase one’s cancer risk. However, many of my young cancer patients are thin, fit, non-smokers. Some scientists believe there is another underlying cause in our physical environment contributing to the problem. Chemicals in the environment including pollutants in the air, water, and soil, as well as pesticides may play a role.
It also seems reasonable that our diets are contributing to colorectal cancer development. Processed foods (deli meats, hot dogs) and red meat have been associated with colorectal cancer. While the consumption of these meats should be limited to moderation, for most of us, cutting out processed food altogether can be quite daunting. Even a home cooked meal frequently uses processed ingredients from boxed pasta, pasta sauce, salad dressing, and dry powders and sauces used in everyday cooking.
In addition, there is mounting evidence that an interplay between our gut bacteria (the microbiome) and our immune system may be involved. A diet low in fiber may contribute to overgrowth of pathogenic bacteria and underrepresentation of good healthy bacteria in our gut. A diet high in fiber (fruits, vegetables, grains, legumes) on the other hand can promote good gut bacterial health.
How does colonoscopy prevent colorectal cancer?

Colonoscopy is the gold-standard colorectal cancer screening tool. In this test, a small camera is introduced into the anus and advanced through the large intestine or colon while you are comfortably sedated with twilight anesthesia. Since cancers generally arise from precancerous polyps, any polyps found at the time of colonoscopy are removed to PREVENT progression to cancer. Colonoscopy is a better test than the non-invasive stool test Cologuard because while Cologuard finds 92% of cancers, it only finds 42% of advanced precancerous polyps making it a great tool for diagnosing cancer but not preventing it. The recommended age to begin colorectal cancer screening is 45 for average risk persons. If you have symptoms including bleeding, change in bowel habits, bloating, new constipation or diarrhea, speak to your doctor because you may need a colonoscopy sooner. If you have a family history of colorectal cancer or polyps or multiple other cancers then the recommended colonoscopy age is younger. Talk to your doctors.
What can I do to minimize my risk of colorectal cancer?
- Add fruits, veggies, whole grains, and legumes to your diet. This will help increase your gut microbial diversity and create an immune environment to prevent colorectal cancer. Fiber supplements won’t work the same.
- Don’t use tobacco
- Limit alcohol intake to 2 drinks a day for men, 1 for women
- Minimize red meat intake
- Minimize processed meats
- Exercise regularly
- Get screened for colorectal cancer. Colonoscopy is the best screening and prevention tool – see recommendations below on when you should have this test!

When should I have a colonoscopy?
First, let’s determine if you are average risk or high risk for colorectal cancer.
You are considered average risk if:
- you have no personal or family history of colorectal cancer or polyps, and
- you have no familial genetic condition, and
- you do not have ulcerative colitis or Crohn’s disease
- you have no symptoms such as blood in your stool, new constipation or diarrhea, bloating or change in bowel habits
Average risk individuals should have a colonoscopy at age 45.
You are considered high risk if you have:
- personally had colon polyps
- personal history of colorectal, uterine, ovarian, stomach, pancreas, or kidney cancer
- family history of colorectal cancer or polyps
- ulcerative colitis or Crohn’s disease
- familial genetic condition such as Lynch syndrome or familial adenomatous polyposis
For high risk patients,
- If you have a family history of colorectal cancer or polyps you should have your first colonoscopy at age 40 or 10 years younger than when the family member was diagnosed. So if your brother had a colon polyp at age 35, you should have a colonoscopy at age 25.
- If 3 or more members of your family are affected by cancer (including colorectal, uterine, ovarian, stomach, pancreas, kidney) or if cancers occurred at a young age (under 50) you should be evaluated for genetic testing and have a colonoscopy – ask your doctors on what age to start – some genetic syndromes recommend colonoscopy in your teems and 20s.
- If you have inflammatory bowel disease (ulcerative colitis or Crohn’s disease) speak to your gastroenterologist about frequency of colonoscopy screening. Usually we recommend colonoscopy every 1-2 years for patients with IBD after 8 years of diagnosis.
What if I have symptoms?
If you have a change in bowel habits, new bloating, diarrhea or constipation or blood in your stool you may need a colonoscopy. Talk to your doctor. If you have bright red blood per rectum, the most common diagnosis is hemorrhoids, but rectal cancers can also present this way. Make sure you are evaluated with a digital rectal examination and anoscopy for any persistent bleeding.
Remember than ongoing symptoms should not be ignored. Most patients with young-onset colorectal cancer have worsening symptoms for many months before a diagnosis is finally made. Often times, young patients with cancer are diagnosed with advanced or metastatic cancers because symptoms tend to be overlooked.

While the trend in young-onset cancers is scary, there is enormous research effort focusing on this issue.
For example, one of the studies I am involved in is development of a novel blood based assay to detect early onset colorectal cancer in collaboration with scientist Megan Hitchins, PhD and at the Cedars Sinai Medical Center and Samuel Oschin Comprehensive Cancer Institute. I am hopeful that these collaborative focused efforts will help turn the corner on this trend in the upcoming years. In the mean time, we have to raise awareness so patients can make knowledgeable health decisions and clinicians can guide patients toward appropriate prevention and screening for colorectal cancer.
