Information about Colon Cancer

According to the American Cancer Society, about 96,830 new cases of colon cancer and 40,000 new cases of rectal cancer will be diagnosed in the United States in 2014. Colorectal cancer is the third most common cause of death from cancer, killing more than 50,000 Americans each year. The good news is that most colorectal cancers and deaths can be prevented.

Causes of colorectal cancer

Cancer occurs when a genetic mutation causes cells in the body to reproduce in a rapid, disorderly, and dangerous manner. The precise cause of this mutation is unclear, but it appears to result from a combination of individual and environmental risk factors.

Risk factors for colorectal cancer include:

  • increasing age
  • polyps in the colon or rectum or a history of these polyps
  • especially an inherited condition called familial polyposis
  • breast, endometrial, or ovarian cancer
  • ulcerative colitis or Crohn's disease
  • inherited syndromes such as hereditary non-polyposis colon cancer (Lynch syndrome), Turcot syndrome, or Peutz-Jeghers syndrome
  • a close relative (mother, father, or sibling) diagnosed with colorectal cancer before age 60
  • dietary factors, such as eating red and processed meats
  • obesity and inactivity
  • smoking
  • type 2 diabetes
  • heavy alcohol use
  • racial background of African-American or Eastern European Jewish descent

Symptoms of colorectal cancer

Colorectal cancer often produces no symptoms in its early stages, which is why screening is so important. However, any of the following symptoms should prompt a visit to your doctor:

  • frequent, unexplained abdominal pain or cramps
  • blood in or on your stool or blood in the toilet or on your underwear after passing stool
  • an increase or decrease in bowel movements
  • alternating between frequent bowel movements and constipation
  • passing narrowed stools
  • weakness and fatigue
  • a feeling of having to move your bowels when it's not necessary
  • a temporary change in your bowel movements
  • unexplained weight loss

Screening for colorectal cancer

All adults age 50 and over should be screened for colorectal cancer to detect polyps before they become cancerous. Screening methods include:

  • colonoscopy every 10 years
  • flexible sigmoidoscopy every five years
  • barium enema every five years
  • virtual colonoscopy every five years

The following tests can also help detect cancer but not polyps:

  • fecal occult blood test every year
  • fecal immunochemical test every year
  • stool DNA test (ideal interval not determined)

Besides regular screening, lifestyle measures may reduce colorectal cancer risk. These include

  • eating a diet low in animal fat and high in fruits and vegetables
  • exercising regularly
  • maintaining a healthy weight
  • not smoking
  • not drinking alcohol excessively

Updated by Remedy Health Media

Publication Review By: H. Franklin Herlong, M.D.

Published: 29 Mar 2011

Last Modified: 14 Nov 2014