8 Things to Know About Colorectal Cancer Screenings

Cases decreasing among older adults, increasing among younger

A colorectal cancer screening questionnaire asking if you are at risk.

Cases decreasing among older adults, increasing among younger

It’s not something most people want to talk about, but by age 45 — or maybe younger if you have risk factors — you should have a conversation with your doctor about colorectal cancer.

Regular screening exams for colorectal cancer — also known as colon cancer and rectal cancer depending on where it starts — can find cancer at an early stage before it has spread.

“When colorectal cancer is diagnosed at earlier stages, treatment options are more successful,” says Walter Coyle, MD, a gastroenterologist at Scripps Clinic. “That is why it’s important when the time comes to talk to your doctor about when and how you should be screened for colon cancer.”

The risk of getting colorectal cancer increases as you get older. Other risk factors include having inflammatory bowel disease, family history of colorectal cancer or a genetic syndrome.

There are two main types of screening for colorectal cancer: stool-based tests and direct visual exams.

Here are eight things you should know about this serious disease that is preventable through screening and early detection.

1. Colorectal cancer is third most common cancer

The American Cancer Society estimates that 106,590 new cases of colon cancer and 46,220 new cases of rectal cancer will be diagnosed in the United States in 2024.

Colorectal cancer is the third leading cause of cancer-related deaths in men and fourth leading cause of cancer-related deaths in women in the U.S. It is expected to cause about 52,010 deaths this year.

Men have a slightly higher risk than women of developing the disease. American Indian, Alaska Natives and African Americans have the highest rates of colorectal cancer in the U.S.

It’s important to note that each person's risk is different, depending on their risk factors for colorectal cancer.

2. Colorectal cancer develops slowly, with few early signs or symptoms

Colorectal cancer almost always starts with an abnormal growth known as a polyp in the colon or rectum. Not all polyps are malignant.

A polyp can take as many as 10 to 15 years to develop into cancer. There are generally few symptoms during the early stages of the disease.

As the disease progresses, symptoms may include blood in the stool, rectal bleeding or abdominal pain. It may also include a change in bowel habits that lasts for a few days or more, such as diarrhea, constipation, or narrowing of the stool. If you notice any of these symptoms, call your doctor.

“Other conditions may also cause these symptoms, so it is important to identify the cause and get treatment,” Dr. Coyle says.

3. Screening can prevent colorectal cancer

Because polyps in the colon or rectum grow so slowly, the goal is to find and remove them before they become cancerous.

When colorectal cancer is found early, the 5-year survival rate is about 90 percent, according to the American Cancer Society. Only 4 in 10 colorectal cancers are found at its early stage. When cancer has spread outside the colon or rectum, survival rates are lower.

Several types of colorectal screening tests are available. Some only detect potentially cancerous growths, while others detect and remove them.

4. Colorectal cancer is declining among older adults

The rate of colorectal cancer cases has been declining since the mid-1980s, due largely to more people getting screened. Colorectal polyps can be found by screening and removed before they can develop into cancers.

The decline has been mostly among adults 50 and older. About 7 in 10 adults aged 50 to 75 are up to date with colorectal cancer screenings, according to the Centers for Disease Control and Prevention.

5. Colorectal cancer is rising among younger adults

Colorectal cancer cases among people younger than 50 have been increasing since the mid-1990s, according to the American Cancer Society.

Regular screening for people at average risk is recommended at age 45. The recommended age was lowered a few years ago from 50 to 45 by the U.S. Preventive Services Task Force and the American Cancer Society. The change came in response to studies that show a rise in the rates of colorectal cancer among younger adults.

“If you have a family history of colorectal cancer or risk factors, such as inflammatory bowel disease, your doctor may recommend having your first screening at a younger age,” Dr. Coyle says.

Younger adults concerned about colorectal cancer should watch out for symptoms that are consistent with the disease, including pain, bleeding, altered bowel habits or changes in stool patterns.

6. Colonoscopy is the 'gold standard' of screening tests

There are two types of screening recommended for colorectal cancer: stool-based sample tests and visual screening procedures.

A colonoscopy is a visual screening procedure that is considered the “gold standard” for colorectal cancer screening. It is performed while you are sedated, so you do not feel or see anything.

A doctor inserts a flexible tube with a small camera into the rectum to examine the entire length of the colon. If precancerous polyps are found, they often can be removed during the procedure. For most people, colonoscopy screenings should be repeated every 10 years.

A flexible sigmoidoscopy is similar to a colonoscopy procedure. However, it uses a shorter tube to view only the lower third of the colon. Because the colon needs to be empty for these procedures, you must drink only clear liquids for 24 hours and take a special prescription laxative to clear your colon.

A FIT, or fecal immunochemical test, analyzes a stool sample for signs of blood from cancer. No prep is necessary. However, this test is not as thorough as a colon exam. If cancer is suspected or the FIT test is positive, a colonoscopy may be needed. Usually, the FIT test is performed every year.

7. Some risk factors can’t be changed

Some risk factors can be changed. Others cannot. Being older is one. Colorectal cancer is still more common after age 50.

Other risks that cannot be changed include genetic predispositions and family or personal history of colorectal cancer or precancerous colorectal polyps. A personal history of inflammatory bowel disease or type 2 diabetes also increases the risk of colorectal cancer.

8. But you can change lifestyle-related risk factors

Many lifestyle-related risk factors associated with colorectal cancer can be changed, including diet and weight.

The risk of developing and dying from colorectal cancer is higher if you are:

  • Overweight or obese
  • Not physically active
  • A tobacco smoker
  • A moderate to heavy alcohol user

Eating healthy, exercising and maintaining a healthy weight can lower that risk. Avoiding smoking and lowering alcohol use are also strongly recommended.

While more research is needed, a study in JAMA Oncology showed that drinking coffee, caffeinated or decaffeinated, may extend survival time in people with colorectal cancer.

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