Colorectal Cancer Information

Summary | Risk Factors
Send page to printer

Doctors cannot always explain why one person gets cancer and another does not. However, scientists have studied general patterns of cancer in the population to learn what things around us and what things we do in our lives may increase our chance of developing cancer.

Anything that increases a person's chance of developing a disease is called a risk factor; anything that decreases a person's chance of developing a disease is called a protective factor. Some of the risk factors for cancer can be avoided, but many cannot. For example, although you can choose to quit smoking, you cannot choose which genes you have inherited from your parents. Both smoking and inheriting specific genes could be considered risk factors for certain kinds of cancer, but only smoking can be avoided. Prevention means avoiding the risk factors and increasing the protective factors that can be controlled so that the chance of developing cancer decreases.

Although many risk factors can be avoided, it is important to keep in mind that avoiding risk factors does not guarantee that you will not get cancer. Also, most people with a particular risk factor for cancer do not actually get the disease. Some people are more sensitive than others to factors that can cause cancer. Talk to your doctor about methods of preventing cancer that might be effective for you.

Purposes of this summary

The purposes of this summary on colorectal cancer prevention are to:

• Give information on colorectal cancer and how often it occurs.
• Describe colorectal cancer prevention methods.
• Give current facts about which people or groups of people would most likely be helped by following colorectal cancer prevention methods.

You can talk to your doctor or health care professional about cancer prevention methods and whether they would be likely to help you.

Back to Top

Colorectal cancer

Cancer of the colon or rectum is often called colorectal cancer. The colon and the rectum are part of the large intestine, which is part of the digestive system.

The Digestive System

 

Tumors found in the colon or rectum may be benign (noncancerous) growths of tissue (polyps) or malignant cancerous growths of tissue that may spread to other parts of the body.

However, there are some warning signs for colorectal cancer that you should be aware of. See your physician if you experience any of the following symptoms:

.  A change in bowel habits such as diarrhea, constipation, or narrowing of the stool that lasts for more than a few days;

.  A feeling that you need to have a bowel movement that is not relieved by doing so;

.  Rectal bleeding or blood in the stool;

.  Cramping or steady abdominal (stomach area) pain;

.  Decreased appetite;

.  Weakness and fatigue;

.  Jaundice (yellow-green discoloration of the skin and white part of the eyes).

These symptoms do not guarantee a diagnosis of cancer. They may indicate other problems, such as diseases of the stomach, gallbladder or pancreas, or hemorrhoids. These symptoms are signs that your body is giving you to indicate that something is wrong. The earlier a cause is found, the better the outcome.

Significance of colorectal cancer

Colorectal cancer is the second leading cause of cancer deaths in the United States. The number of new cases of colorectal cancer in the United States has been decreasing slightly, and the number of deaths due to colorectal cancer has been decreasing. The risk of colorectal cancer tends to increase after the age of 40.

Colorectal cancer prevention

Colorectal cancer can sometimes be associated with known risk factors for the disease. Many risk factors are modifiable though not all can be avoided.

Diet and Lifestyle: Diet appears to be associated with colorectal cancer risk. Among populations that consume a diet high in fat, protein, calories, alcohol, and meat (both red and white) and low in calcium and folate, colorectal cancer is more likely to develop than among populations that consume a low-fat, high-fiber diet. A diet low in vitamin D may also increase the risk of colorectal cancer. One study has found that a diet low in fat and high in fiber, fruits, and vegetables does not reduce the risk of colorectal cancer recurrence during a three to four year period. A diet high in saturated fat combined with a sedentary lifestyle may increase the risk of colorectal cancer. There is also evidence that smoking cigarettes may be associated with an increased risk of colorectal cancer.

Nonsteroidal Anti-Inflammatory Drugs: Some studies have shown that the use of nonsteroidal anti-inflammatory drugs (NSAIDs) may be associated with a reduced risk of colorectal cancer.

Polyp Removal: The removal of polyps in the colon may be associated with a reduced risk of colorectal cancer.

Female Hormone Use: Postmenopausal female hormone use is associated with a reduced risk of colon cancer but not rectal cancer.

Screening

The best way to prevent colorectal cancer is through screening. There are several different ways a doctor may screen for colorectal cancer. The doctor's choice of test depends on your individual risk and if there are any symptoms present.

The American Cancer Society has established basic guidelines for having colorectal screening tests. The frequency and type of test depends on risk level.

• Digital rectal exam: A physician examines the rectum with a gloved finger and checks for lumps or abnormalities.
• Stool blood test: Tests for blood in the stool (fecal occult blood test).
• Sigmoidoscopy: A physician examines the portion of the colon extending from the anus to the top of the left side of the colon (descending colon) using a lighted tube.
• Colonoscopy: A physician examines the entire right (ascending and transverse) and left sides of the colon using a lighted tube.
• Double Contrast Barium Enema: A series of x-rays are taken of the colon and rectum after the patient is given an enema with a white, chalky solution that contains barium to outline the colon and rectum.

Depending on individual clinical judgment, the American Cancer Society recommends that most people at moderate to high risk for colorectal cancer have periodic colonoscopies-typically every 3 to 5 years. In a colonoscopy, the entire bowel is visualized. The likelihood of removing all polyps in the colon is much greater, and therefore, the risk of colorectal cancer is reduced. The risk for colorectal cancer increases after age 50. Thus, the American Cancer Society recommends that both men and women should follow these screening guidelines beginning at age 50:

• Yearly fecal occult blood test and flexible sigmoidoscopy every 5 years; or
• Colonoscopy every 10 years

Risk factors increase the likelihood of getting colorectal cancer.You should undergo screening more often if you have any of the following risk factors:

.  Family history of colorectal cancer or polyps [a first-degree relative (i.e., brother, sister, mother, or father) younger than 60 or in two first-degree relatives of any age];

.  Family history of colorectal cancer syndromes [e.g., familial adenomatous polyposis (FAP), a condition characterized by many polyps on the inner lining of the colon and hereditary non-polyposis colon cancer];

.  Personal history of colorectal cancer or adenomatous polyps;

.  Personal history of chronic inflammatory bowel disease;

.  Personal history of ovarian, endometrial, or breast cancer;

.  Personal history of chronic ulcerative colitis or Crohn's colitis.

 

Back to Top
Send page to printer