About Colorectal Cancer

What is colorectal cancer?

Colorectal cancer is cancer that grows in the colon or rectum. Colorectal cancer can start anywhere in the large intestine. Most colorectal cancers start as polyps— abnormal growths—inside the colon or rectum. Over a long period of time, polyps may become cancerous.

What causes colorectal cancer, and who is at risk
of developing it?

The exact cause of most colorectal cancers is not well known. About 75% of colorectal cancers occur in people who do not have any risk factors.  However, some things may increase a person’s risk of developing colorectal cancer. Those who are at increased or high risk should talk to their healthcare provider about when to start screening.  Some factors include:

• Age (people over age 50 have a higher risk)
• A personal or family history of colorectal polyps or colorectal cancer
• Inflammatory bowel disease (ulcerative colitis or Crohn’s disease)
• A genetic syndrome such as familial adenomatous polyposis (FAP) or hereditary non-polyposis colorectal cancer (Lynch syndrome)
• Smoking
• Excess alcohol consumption

• Obesity

What are the symptoms of colorectal cancer?

People who have polyps or colorectal cancer don't always have symptoms. This is especially true in the early stages of cancer. If there are symptoms, they may include:

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

If you have any of these symptoms, talk to your doctor. These symptoms may be caused by something other than cancer, but the only way to know is to see your doctor.

Is there anything I can do to reduce my risk for colorectal cancer?

The best way to lower your risk of colorectal cancer is by having regular screening tests beginning at age 50. Scientific studies have shown that screening reduces deaths from colorectal cancer. Screening tests can find and remove polyps (abnormal growths) in the colon and rectum before they turn into cancer. If everyone aged 50 or older had regular screening tests, up to 60% of deaths from colorectal cancer could be prevented.

Studies also show that people who are at a healthy weight and are physically active often have a lower risk of colorectal cancer.

The role of diet in preventing colorectal cancer is not well known. In general, medical experts recommend a diet low in animal fats and high in fruits, vegetables and whole grains. This diet also may reduce the risk of colorectal cancer. In addition, researchers are trying to understand how the use of certain vitamins and supplements such as NSAIDs, Vitamin D, calcium, and folic acid may affect the risk for colorectal cancer.

What is cancer screening?

Screening is when a test is used to look for a disease before there are any symptoms. Cancer screening tests, including those for colorectal cancer, are effective when they can detect disease early. Detecting disease early can lead to more effective treatment. (These are different from diagnostic tests, which are used when a person has symptoms and are intended to find out what is causing the symptoms.)

Why should I get screened for colorectal cancer?

Screening for colorectal cancer saves lives. Colorectal cancers almost always develop from precancerous polyps (abnormal growths) in the colon or rectum. Screening tests can find polyps, so they can be removed before they turn into cancer. Screening tests also can find colorectal cancer early, when treatment works best and the chance for a full recovery is very high. Having regular screening tests beginning at age 50 could save your life.

What are the screening tests for colorectal cancer?

Beginning at age 50 for average-risk people, several screening tests can be used to find polyps or colorectal cancer. Each can be used alone. Sometimes they are used in combination with each other. The US Preventive Services Task Force recommends colorectal cancer screening for men and women aged 50 to 75 using one of the screening tests listed below. The task force’s recommendations for how often you should have them done are listed with each test. Talk to your doctor about which test or tests are right for you. If you are older than 75, ask your doctor if you should be screened.

• High-Sensitivity FOBT (Stool Test): There are two types of fecal occult blood tests (FOBTs). One uses the chemical guaiac to detect blood. The other, a fecal immunochemical test (FIT), uses antibodies to detect blood in the stool. You receive a test kit from your healthcare provider. At home, you use a stick or brush to obtain a small amount of stool. You return the test kit to the doctor or a lab, where the stool samples are checked for anything unusual. How often: Once a year.
• Flexible Sigmoidoscopy Plus High-Sensitivity FIT/FOBT: For this test, the healthcare provider puts a short, thin, flexible, lighted tube into your rectum. The doctor checks for polyps or cancer inside the rectum and lower third of the colon. How often: Every 5 years, with mid-interval high-sensitivity FIT/FOBT during year 3.
• Colonoscopy: The doctor uses a long, thin, flexible, lighted tube to check 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. Colonoscopy also is used as a follow-up test if anything unusual is found during one of the other screening tests. How often: Every 10 years.

What about other colorectal cancer screening tests?

These tests are not recommended by the U.S. Preventive Services Task Force. However, they may be used in some settings and other groups may recommend them. Many insurance plans don't cover these tests. If anything unusual is found during the test, you likely will need a follow-up colonoscopy.

• Double-contrast barium enema: You receive an enema with liquid called barium, followed by an air enema. This allows the doctor to see the outline of your colon on an X-ray.
• Virtual colonoscopy: X-rays and computers are used to produce an image of the entire colon. The image of the colon can then be viewed on a computer screen.
• Stool DNA test: You collect an entire bowel movement and send it to a lab to be checked for cancer cells.

How will I pay for colorectal cancer screening?

Most insurance plans help pay for colorectal cancer screening for people who are aged 50 or older. Medicare also helps pay for screening. If you are uninsured or if your plan does not cover screening, you may be eligible to receive services through the New Mexico Colorectal Cancer Program.