Q. What is colorectal cancer?
A. Cancer is a group of diseases in which there is abnormal and uncontrolled growth of cells in the body. If left untreated, malignant (or cancerous) cells can spread to other parts of the body.

Colorectal cancer can begin anywhere in the large intestine (colon and rectum). The majority of colorectal cancers begin as polyps—abnormal growths—inside the colon or rectum that may become cancers over a long period of time.

Q. How does colorectal cancer affect the U.S. population?
A. Of cancers that affect both men and women, colorectal cancer is the second-leading cancer killer in the U.S.

Q. What causes colorectal cancer, and who is at risk of developing it?
A. About 75% of colorectal cancers occur in people with no known risk factors. Some conditions that may increase a person's risk of developing colorectal cancer include having a personal or family history of colorectal polyps or colorectal cancer, inflammatory bowel disease (ulcerative colitis or Crohn's disease), or a genetic syndrome.

Q. What are the symptoms of colorectal cancer?
A. People who have polyps or colorectal cancer don't always have symptoms, especially at first. Someone could have polyps or colorectal cancer and not know it. If there are symptoms, they may include blood in or on a stool (bowel movement); pains, aches, or cramps in the stomach that don't go away, losing weight, or a change in bowel habits (constipation or diarrhea).
These symptoms may be caused by something other than cancer. However, the only way to know what is causing them is to see your doctor.

Q. Is there anything I can do to reduce my risk for colorectal cancer?
A. There is strong scientific evidence that having screening tests for colorectal cancer beginning at age 50 reduces deaths. Screening tests can find precancerous polyps in the colon and rectum, and polyps can be removed before they turn into cancer.

Studies have also shown that increased physical activity and maintaining a healthy weight can decrease the risk for colorectal cancer. Research is underway to determine whether dietary changes may decrease the risk for colorectal cancer.

Overall, the most effective way to reduce your risk of colorectal cancer is by having regular colorectal cancer screening tests beginning at age 50.

Q. What is cancer screening?
A. Cancer screening tests are effective when they can detect disease early because early detection can lead to more effective treatment. (Diagnostic tests are used when a person has symptoms and are intended to find out what is causing the symptoms.)

Q. Why should I get screened for colorectal cancer?
A. Screening for colorectal cancer saves lives. Colorectal cancers almost always develop from precancerous polyps 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.

Q. What are the screening tests for colorectal cancer?
A. Several screening tests can be used to find polyps or colorectal cancer. Talk to your doctor about which test or tests are right for you. Learn about the various tests available at
http://www.icsi.org/for_patients/save_500_lives__boost_colorectal_screenings/screening_options_for_colon_cancer/.

Q. How do I know which screening test is right for me?
A. Scientific data do not currently suggest that there is a single "best test" for any one person. Each test has advantages and disadvantages. Patients and their doctors are encouraged to discuss the benefits and potential risks associated with each screening option as they decide which test to use and how often to be tested. Which test to use depends on the patient's preferences and medical condition, the likelihood that the patient will have the test, and the resources available for testing and follow-up.

Materials from the Centers for Disease Control: http://www.cdc.gov/cancer/colorectal.