Colorectal cancer, commonly known as bowel cancer, is a cancer from uncontrolled cell growth in the colon, rectum, or appendix. Symptoms typically include rectal bleeding and anemia which are sometimes associated with weight loss and changes in bowel habits.
Most colorectal cancer occurs due to lifestyle and increasing age with only a minority of cases associated with underlying genetic disorders. It typically starts in the lining of the bowel and if left untreated, can grow into the muscle layers underneath, and then through the bowel wall. Screening is effective at decreasing the chance of dying from colorectal cancer and is recommended starting at the age of 50 and continuing until a person is 75 years old. Localized bowel cancer is usually diagnosed through sigmoidoscopy or colonoscopy.
- Colorectal cancer is a disease in which cells in the colon or rectum become abnormal and divide without control, forming a mass called a tumor;
- The exact causes of colorectal cancer are not known. However, studies show that certain factors increase a person's chance of developing colorectal cancer;
- Health care providers may suggest one or more tests for colorectal cancer screening, including a fecal occult blood test (FOBT); sigmoidoscopy; regular, or standard, colonoscopy; virtual colonoscopy; or double contrast barium enema (DCBE);
- People should talk with their health care provider about when to begin screening for colorectal cancer, what tests to have, the benefits and risks (potential harms) of each test, and how often to schedule appointments; and
- New methods, such as the genetic testing of stool samples, to screen for colorectal cancer are under study.
What are the risk factors for colorectal cancer?
While we do not know the exact cause of most colorectal cancers, there are certain known risk factors. A risk factor is something that affects a person's chance of getting a disease.
Some risk factors - like smoking, can be controlled. Others, such as a person's age, can't be changed.
National Cancer Institute Fact Sheet - http://www.cancer.gov/cancertopics/factsheet/detection/colorectal-screening