Colon cancer in young adults: What you need to know

Colorectal cancer cases are on the decline overall. Research shows this is because more people are getting regular colorectal cancer screenings, which can prevent precancerous polyps from becoming cancer.

But the disease is rising sharply in people under age 50, most of whom are years away from getting their first screening colonoscopy. Colorectal cancer screening isn’t recommended until age 45 for most people. And most young patients will be diagnosed with stage III and IV colorectal cancer. That means their cancer is being found later when it’s harder to treat.

I often get asked questions about colorectal cancer in young adults. Here's what you should know.

Why is colorectal cancer on the rise among young adults?

We don’t know exactly why so many people under age 50 are being diagnosed with colorectal cancer. 

What we do know is that about 20% of colorectal cancer patients under age 50 have an inherited genetic mutation that causes their cancer.

Family history also plays a role in causing a portion of colorectal cancers in these young adults, but we're still researching what is causing the disease in the remainder of the group.

Can you have colorectal cancer in your 20s?

Yes, you can have colorectal cancer in your 20s and even younger than that. But it’s not very common, and many colorectal cancer patients diagnosed at that age have an inherited genetic predisposition.

But I have noticed a shift. When I started my career 15 years ago, most of the patients with young-onset colorectal cancer were in their 40s. Now, I’m seeing more patients in their 30s and 40s.

Why is it important to know your family's cancer history?

Knowing your family’s cancer history can provide you with important clues about your own risk for colorectal cancer. Trace out three generations if possible. You want to know who had cancer and how you are related, what type(s) of cancer they had and at what age each person was diagnosed. Tracing all first- and second-degree relatives is best.

First-degree relatives are your birth parents, siblings and children. Second-degree relatives are aunts and uncles, nephews and nieces and grandparents.

Having a family history of cancer doesn’t mean you will get cancer. But this information lets you know if you should start screening for colorectal cancer early. The earlier cancer is detected, the easier it is to treat. Colonoscopies can help prevent cancer because we can remove precancerous polyps or lesions before they become cancer.

Even if you do not have a family history of cancer, be sure to see a doctor if you notice any new or unusual changes in your body. And keep up with recommended colorectal cancer screenings. 

What should younger colorectal cancer patients know about genetic counseling and testing?

Genetic counseling and genetic testing are critical for any young person diagnosed with colorectal cancer. If a patient is diagnosed with an inheritable gene mutation or a hereditary cancer syndrome, like Lynch syndrome, that gives us an explanation for why they developed colorectal cancer. That can help us tailor our treatment.  It also helps us look for and prevent other cancers the patient may be at risk for as a part of the same cancer syndrome.

Knowing you have a genetic mutation is vital information for your whole family. It can help your family members decide to get tested and monitor their cancer risks.

At MD Anderson, our Gastrointestinal Cancer Center offers clinical cancer genetics services for all cancer patients.  In particular, our Young-Onset Colorectal Cancer Program offers universal genetic counseling and testing for all colorectal cancer patients diagnosed under age 50 because we don't want to miss a hereditary diagnosis. For patients who test positive, we have a specialized Familial High-Risk Gastrointestinal Cancer Clinic where we follow all the families with cancer syndromes. 

What colorectal cancer symptoms should people of all ages watch for?

Whether or not you have a family history of cancer, you should be familiar with your body and look out for colorectal cancer symptoms. Remember: often patients with colorectal cancer have no symptoms at all. But, if you do have a symptom, don’t be shy about talking to your doctor about it.

The most common symptoms to watch out for are:

• Rectal bleeding with or without pain
• Blood in the stool or toilet with or after a bowel movement
• A change in bowel pattern
• Anemia

Other common symptoms may include:

• Bloating or full feeling or cramping
• A change in the size or shape of your stool
• A new need for straining to evacuate stool
• Unexplained weight loss
• Fatigue or reduced stamina

If you have any of these symptoms or think you may have an inherited risk of colorectal cancer, talk to your doctor about getting tested. 

What is the survival rate for younger colorectal cancer patients?

The prognosis depends on the cancer’s stage. The earlier the stage of the tumor, the easier it is to treat and the better the outcome.

While each patient’s case is unique and requires personalized treatment, general figures from the American Cancer Society show that:

• The five-year survival rate for colorectal cancer that has not spread (stage I or II) is 94% in patients under age 50.
• The five-year survival rate drops to 80% for patients with cancer that has spread to the lymph nodes.
• Patients under age 50 with stage IV colorectal cancer have a 21% five-year survival rate.

We have made advances in treating colorectal cancer. For example, immunotherapy has completely revolutionized the care for colorectal cancer patients with Lynch syndrome. Often, these patients can be cured. Research is also being done to better treat patients with metastatic colorectal cancer, namely those with the KRAS genetic mutation.

Do all young colorectal cancer patients need an ostomy bag?

Rectal cancer is more common than colon cancer in young adults. Many young rectal cancer patients worry they will need an ostomy bag during treatment. An ostomy involves surgically creating a hole in the digestive tract to allow the body to pass waste. The ostomy bag is attached to the hole to collect the waste.

Sometimes patients will need a temporary ostomy as part of their rectal cancer treatment. Some patients may need an ostomy for about two months; others may need an ostomy longer while some patients will need a permanent ostomy.

We offer a lot of support to patients who need ostomies. Through the Young-Onset Colorectal Cancer Program, patients can connect with other young cancer patients through support groups, or speak to care coordinators, social work counselors and wound ostomy specialists.

Having an ostomy can be a lifestyle change, but it’s a skill you can learn and adapt to. I tell my patients they can do the same things with an ostomy that they could without one. 

What can younger people do to reduce their risk of colorectal cancer?

It's never too early to start making healthy lifestyle choices to reduce your risk for colorectal cancer. Here are some basics to get started:

• Be physically active. Aim for at least 150 minutes of moderate exercise or 75 minutes of vigorous exercise each week.
• Limit red meat and avoid processed meat.
• Eat a healthy diet. Start by filling at least two-thirds of your plate with vegetables, whole grains, fruits and beans. Fill the remaining one-third with lean animal protein or plant-based protein.
• Limit alcohol.
• Don't smoke, vape or use any other form of tobacco. If you do use tobacco, quit.

Finally, if your doctor thinks you should get a colonoscopy to screen for colorectal cancer, do it. Men and women at average risk for colorectal cancer should get a screening colonoscopy every 10 years beginning at age 45. 

Knowing your family history and genetic risk will help your doctor decide when you should start colorectal cancer screening. 

While colonoscopy is the gold standard for colorectal cancer screening, there are other ways to test for colorectal cancer. Talk to your doctor to see which test is right for you.

Colorectal cancer screening has huge benefits. It prevents cancer, and it prevents death. Research proves it.

Y. Nancy You, M.D., is a colon and rectal cancer surgeon and director of the Young-Onset Colorectal Cancer Program at MD Anderson.

Request an appointment at MD Anderson online or call 1-877-632-6789.