Colorectal Cancer

What is cancer?

The body is made up of many types of cells. Normally, cells grow, divide and die. Sometimes, cells mutate (change) and begin to grow and divide more quickly than normal cells. Rather than dying, these abnormal cells clump together to form tumors. If these tumors are cancerous (also called "malignant"), they can invade and kill your body's healthy tissues. From these tumors, cancer cells can metastasize (spread) and form new tumors in other parts of the body. By contrast, noncancerous tumors (also called "benign") do not spread to other parts of the body.

What is colorectal cancer?

Colon cancer begins in the large intestine (called the colon). Rectal cancer begins in the rectum, the part of the large intestine closest to the anus (the outside opening to the intestine). These forms of cancer have many common features. Sometimes they are referred to together as colorectal cancer.
Colorectal cancer is the second leading cause of cancer deaths in the United States. Many of these deaths happened because the cancers were found too late to be cured. If colorectal cancer is found early enough, it can usually be cured by surgery.

What are the signs of colorectal cancer?

Most colorectal cancers begin as a polyp (say "pahl-ip"). At first, a polyp is a small, harmless growth in the wall of the colon. However, as a polyp gets larger, it can develop into a cancer that grows and spreads.
See your doctor if you have any of the following warning signs:

  • Bleeding from your rectum
  • Blood in your stool or in the toilet after you have a bowel movement
  • A change in the shape of your stool
  • Cramping pain in your lower stomach
  • A feeling of discomfort or an urge to have a bowel movement when there is no need to have one

Other conditions can cause these same symptoms. You should be checked by your doctor to find the reason for your symptoms.

What are screening tests for colorectal cancer?

Screening tests are used to find cancers before they are large enough to cause any warning signs. Because finding cancer early means that you're more likely to be cured, it is important for you to have appropriate screening tests. Your doctor will choose the tests that are right for you. The following are some screening tests for colorectal cancer:
Digital Rectal Exam. In this exam, your doctor puts his or her gloved finger into your rectum to find any growths. This exam is simple to do and is not painful. However, because this exam can find less than 10% of colorectal cancers, it must be used along with another screening test.

Fecal Occult Blood Test. In this test, your stool is checked for blood that you can't see. Your doctor gives you a test kit and instructions to use at home. Then you return a stool sample to your doctor for testing. If blood is found, another test is done to look for a polyp, a cancer or another cause of bleeding.

Many things that you eat can make this test turn out positive even though you don't really have blood in your stool. This is called a "false-positive" test. These things include some raw vegetables, horseradish, rare red meat, iron supplements and aspirin. Don't eat these things for 2 days before you have a fecal occult blood test. Some medical conditions, like hemorrhoids, can also cause a false-positive test result.

Flexible Sigmoidoscopy. In this test, your doctor puts a thin, flexible, hollow tube with a light on the end into your rectum. The tube is connected to a tiny video camera so the doctor can look at the rectum and the lower part of your colon.
This test can be a bit uncomfortable, but it lets your doctor see polyps when they are very small (before they can be found with a fecal occult blood test). Because flexible sigmoidoscopy may miss cancerous polyps that are in the upper part of the colon, some doctors prefer a screening test called colonoscopy. Your doctor will discuss these options with you.
Double-Contrast Barium Enema. For this test, you are given an enema (injection of fluid into the rectum) with a liquid that makes your colon show up on an x-ray. Your doctor looks at the x-ray to find abnormal spots in your entire colon. If you have an abnormal spot, you are then examined by colonoscopy.

Colonoscopy. Before you have this test, you are given a medicine to make you relaxed and sleepy. A thin, flexible tube connected to a video camera is put into your rectum, and the doctor looks at your whole colon. The tube can also be used to remove polyps and cancers during the exam. Colonoscopy may be uncomfortable, but it is usually not painful.

When should I be screened for colorectal cancer?

Colorectal cancer is more common in older people, so doctors usually screen people 50 years of age and older. Some people have risk factors that make them more likely to get colorectal cancer at a young age. Screening should begin earlier in these people.

You should begin screening at a younger age if any of the following are true about you:

  • Have had colorectal cancer or large polyps in the past
  • Have a close relative (brother, sister, parent or child) who has had colorectal cancer
  • Have ulcerative colitis or Crohn's disease
  • Have a hereditary colon cancer syndrome

If you are in one of these groups, you may also need to be tested more often than a person who doesn't have risk factors for colorectal cancer.

Any one of the following screening programs (with a digital rectal exam at each screening) may be used, beginning at 50 years of age:

  • Fecal occult blood testing every year
  • Flexible sigmoidoscopy every 5 years
  • Fecal occult blood testing every year plus flexible sigmoidoscopy every 5 years
  • Double-contrast barium enema every 5 to 10 years
  • Colonoscopy every 10 years

The American Academy of Family Physicians believes that any of these tests or combinations of tests can be a good screening method. The American Cancer Society and the American Gastroenterological Association have similar guidelines.
Talk to your family doctor to decide which screening tests you should have and how often you should be screened. If you don't have any risk factors for colorectal cancer, you will probably have your first screening test around 50 years of age.

Why is it important to find cancer early?

For many types of cancer, it is easier to treat and cure the cancer if it is found early. There are many different types of cancer, but most cancers begin with abnormal cells growing out of control, forming a lump that's called a tumor. The tumor can continue to grow until the cancer begins to spread to other parts of the body. If the tumor is found when it is still very small, curing the cancer can be easy. However, the longer the tumor goes unnoticed, the greater the chance that the cancer has spread. This makes treatment more difficult.

How do I know if I am at risk for cancer?
Talk to your doctor. He or she can help you understand your risk for cancer if other members of your family have a history of cancer. Your doctor can also help you understand how your risk for cancer is affected by the following:

  • Using or having used tobacco products, such as cigarettes
  • Using alcohol
  • Having eaten a high-fat diet for most of your life
  • Being exposed to chemicals that can cause cancer
  • Being at risk for skin cancer

Depending on your age and your risk factors, your doctor may begin screening you for certain types of cancer. Screening means looking for cancer before it causes symptoms. Some doctors recommend that people who are at high risk or have a family history of cancer be screened regularly. The recommendations vary for different cancers.

If you have any questions, symptoms, or high risk factors for colon cancer, and would like to discuss this with Dr. Amick or Dr. Burroughs, please call and make an appointment at 781-7400.

This information was obtained from the American Family Physicians for nonprofit patient educational use.

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