About Colorectal Cancer

Cancer Screening Saves Lives

Colorectal cancer is the second leading killer in the US among cancers that affect both men and women.  It doesn't have to be.  Routine screening for colorectal cancer, beginning at age 45, can save lives.

Screening tests can find precancerous polyps so they can be removed before they turn into cancer.  Screening tests can also find colorectal cancer early, when treatment works best.

What is colorectal cancer?

Colorectal cancer is cancer that occurs    in the colon or rectum. The colon is the large intestine (the bowel). The rectum connects the colon to the anus.

How does it develop?

Colorectal cancer usually starts with polyps. A polyp is a growth that should not be there. Polyps take years to grow and are common in people over age 45.

Who gets colorectal cancer?

Men and women, regardless of race or ethnicity, can develop colorectal cancer. Mostly it occurs in people aged 45 years or older. Colorectal cancer can lead to death if not detected and treated.  

You may be at increased risk if:

• You or a close relative have had colorectal polyps or colorectal cancer.
• You have inflammatory bowel disease, Chrohn's disease, or ulcerative colitis.
• You have a genetic syndrome such as familial adenomatous polyposis (FAP) or hereditary non- polyposis colorectal cancer (Lynch syndrome).

What are the symptoms of Colorectal Cancer?

Some people with colorectal polyps or colorectal cancer have symptoms which may include:

• Change in your bowel habits
• Blood in or on your stool (bowel movement)
• Stomach pain, aches, or cramps that don't go away
• Unexplained weight loss

If you have any of these symptoms, talk to your healthcare provider. These symptoms may be caused by something other than cancer. However, the only way to know for sure is to see your healthcare provider.

What if I don't have symptoms?

Someone could have polyps or colorectal cancer and not know it. Colorectal cancer almost always develops from precancerous polyps in the colon or rectum. Screening tests can find polyps so that they can be removed before they turn cancerous. Screening tests can also find cancer early, when treatment works best. There are several recommended screening tests. Talk to your healthcare provider about the one that is right for you.

Sixty percent of deaths from colorectal cancer could be prevented if everyone over age 45 got screened regularly.

When should I get screened?

Anyone who is 45 years or older should get screened regularly. Once you turn 75, talk to your healthcare provider to decide whether or not to get screened.

People at higher risk of getting colorectal cancer should get screened earlier than age 45. You may be at higher risk if you've previously had colorectal cancer, if an immediate family member has had it, or if you have inflammatory bowel disease. Although rare, some people have genetic markers for inherited forms of colorectal cancer.

What are the screening tests?

There are several approaches to screening. You should talk to your healthcare provider about which test(s) to choose and how often to use them.

Here are some of the more common tests used for colorectal cancer screening:

FOBT (Fecal Occult Blood Test)

Blood in your bowel movement can be detected by an FOBT. There are two types.

iFOBT: Uses antibodies to detect blood. If you choose this method, ask your healthcare provider for an iFOBT or FIT (Fecal Immunochemical Test).

gFOBT: uses a chemical called guaiac to detect blood. This method is also called gFOBT. If you choose this method, ask your doctor for a high sensitivity gFOBT.

Sigmoidoscopy

The doctor inserts a short, thin, flexible tube to look for polyps or cancer inside the rectum and lower third of the colon.

Colonoscopy

The doctor inserts a long, thin, flexible tube to look for polyps or cancer inside the rectum and the entire colon. During the test, the doctor can find and remove most polyps and some cancers.

Stool DNA with FIT (sDNA-FIT)

FIT is a test that detects altered DNA in stool.  An entire bowel movement is collected and sent to a lab to be checked for cancer cells. This test does not require bowel preparation, sedation, or transportation to and from a physician's office.  Abnormal sDNA-FIT tests may be followed by a colonoscopy.

What happens if a screening test result is abnormal?

An FOBT test result may be abnormal (positive). Not all positives mean that you have cancer. A follow-up test is required. The follow-up to a positive FOBT test would be a colonoscopy. If the doctor finds an abnormality during the colonoscopy, he or she may remove polyps or cancer, and decide whether to do further diagnostic tests or treatments.

If a sigmoidoscopy result is abnormal, your doctor will discuss the follow-up procedure options with you.

If your doctor finds an abnormality during a colonoscopy, he or she may remove polyps or cancer during the procedure. Your doctor will discuss with you whether further diagnostic tests or treatments are  necessary afterward the procedure.

Learn about colorectal cancer screening guidelines

United States Preventive Services Task Force
United States Multi-Society Task Force