March is Colorectal Cancer Awareness Month — wear blue on Friday, March 6!

March is Colorectal Cancer Awareness Month. A new American Cancer Society study shows colorectal cancer is now the leading cause of cancer death in adults under 50 and is the only major cancer where mortality is still rising in younger adults. The recent death of “Dawson’s Creek” actor James Van Der Beek at 48 highlights the risk for younger adults.

UC Davis Comprehensive Cancer Center wants to make sure everyone is aware of the symptoms and how to prevent colorectal cancer. Ankit Sarin is chief of the UC Davis Division of Colorectal Cancer Surgery. He answers questions about colorectal cancer and discusses the best way to detect it early, when it is the most treatable.

Why is colorectal cancer becoming more common among younger adults?

Unfortunately, colorectal cancer is now the number one cause of cancer‑related death in Americans under 50. To put that in perspective: overall cancer deaths in people under 50 have dropped 44% over the past three decades. Colorectal cancer is the alarming exception. It is the only major cancer where death rates are rising in younger adults.

This is a major shift compared to previous generations. If you were born around 1990, your risk is dramatically higher compared to someone born in 1950:

• Two times the risk of colon cancer
• Four times the risk of rectal cancer

We don’t have all the answers yet, but evidence points to a combination of environmental exposures, dietary changes — particularly the rise in ultra-processed foods — sedentary lifestyles, obesity and shifts in the gut microbiome. Importantly, many younger patients have no family history at all, which is why awareness is so critical. Today, one in five colorectal cancer cases occurs in someone under 55.

Is colorectal cancer more dangerous in younger people?

The cancer itself is not necessarily more aggressive, but younger adults tend to be diagnosed much later — often because they don’t expect their symptoms to be cancer. And sometimes because doctors don’t either. The result is devastating: 60–70% of adults under 50 are not diagnosed until the cancer is already at an advanced stage.

When colorectal cancer is caught early, at a localized stage, over 90% of patients survive. That survival rate drops dramatically with advanced disease. James Van Der Beek had spoken publicly about initially dismissing changes in his bowel habits as dietary. That is a story we hear repeatedly from young patients. Early detection truly saves lives.

Recently, actress Catherine O'Hara died of a pulmonary embolism after being diagnosed and treated for rectal cancer. What is the difference between colon and rectal cancer?

Throughout this month, awareness is being raised regarding both types of cancer, which we combine when talking about colorectal cancer. The main difference is location:

• Colon cancer starts in the long, upper portion of the large intestine
• Rectal cancer starts in the final few inches before the anus

Both start as polyps, share risk factors and are detectable — and often preventable — through screening. Rectal cancer more commonly causes rectal bleeding or noticeable stool changes, while colon cancer may initially present with anemia, fatigue or abdominal pain.

Treatment can differ significantly. Rectal cancer often requires radiation and chemotherapy before surgery; colon cancer usually does not. Rectal surgery is more complex due to the tight confines of the pelvic anatomy. Catherine O’Hara’s case also highlights an important complication: cancer increases blood clot risk. Her death from a pulmonary embolism was a direct consequence of her rectal cancer.

Most importantly, standard colorectal cancer screenings catch both types. Screen early.

What is the best way to prevent colorectal cancer?

The most important step is to get screened starting at age 45. This is now covered by insurance with no copay. A colonoscopy doesn’t just detect cancer — it prevents cancer by removing precancerous polyps before they ever become dangerous. It is one of the only cancer screening tools that are both diagnostic and preventive.

To increase your chance of not getting colorectal cancer:

• Eat a diet rich in fiber and limit ultra-processed foods and red/processed meats
• Stay physically active and maintain a healthy weight
• Limit alcohol and avoid tobacco
• Know your family history. If a first-degree relative had colorectal cancer, talk to your doctor about starting to screen earlier

What are the symptoms to watch for?

Some symptoms can be subtle. Here are symptoms you should never ignore:

• Blood in your stool (bright red or dark)
• Persistent changes in bowel habits (diarrhea, constipation, narrowing)
• Unexplained weight loss
• Fatigue
• Abdominal pain or cramping

Don’t assume you’re “too young.” Know the symptoms, listen to your body and stay on track with screening. Colorectal cancer is highly preventable — and highly treatable when caught early. If any symptoms last more than two weeks, talk to your doctor.

When should screening start for colorectal cancer?

For average-risk adults, screening now begins at age 45. This was lowered from 50 by both the United States Preventive Services Task Force and the American Cancer Society in response to the sharp rise in early-onset cases. The screening is covered by insurance with no copay.

You should start even earlier if you are at higher risk:

• Age 40, or
• 10 years before a first-degree relative was diagnosed (whichever comes first)

Here is a sobering local statistic: California ranks 50th out of 50 states in colorectal cancer screening rates, with only 53% of eligible adults up to date. That is not a resource problem — it is an awareness problem. And it is exactly why conversations like this one matter.

Is a colonoscopy the only accurate way to detect colorectal cancer?

Colonoscopy is the gold standard because it does two things no other test can do simultaneously:

• Detects cancer early, when survival exceeds 90%
• Prevents cancer by removing precancerous polyps during the same procedure

But there are other effective options:

• FIT (fecal immunochemical test) — a simple stool test done annually at home
• Cologuard — a stool DNA test done every three years at home

The best screening test is the one you actually complete. Your doctor can help you choose the right option based on your risk and preferences. If a stool test comes back positive, a follow-up colonoscopy is needed.

UC Davis Comprehensive Cancer Center leads in treating complex colon and rectum cancers with the latest therapies for the best quality of life. To learn more or book an appointment, call 916-734-5959.

Related resources:

Listen to this podcast:

• Why are Colon and Colorectal Cancer Incidences Increasing in Younger Populations? A Discussion with Dr. Ankit Sarin