Definition & Prevalence
"Colorectal" refers to the colon and rectum, which comprise the large intestines. Colorectal cancer can originate anywhere in the large intestines. The colon is the large intestine or large bowel. The rectum is the passageway connecting the colon to the anus. The majority of colorectal cancers develop first as polyps. Colorectal polyps are tiny growths inside the colon or rectum that may become cancerous.
In 2012, the American Cancer Society estimates the following statistics for the United States:
- 103,170 new cases of colon cancer
- 40,290 new cases of rectal cancer
- 51,690 deaths from colorectal cancer
Colorectal Cancer Risk Factors
Overall, colorectal cancers are the third most common cancers in men and women, and the second leading cause of cancer death in the United States. Colorectal cancer is most common in people aged 50 years and older and the risk increases with age. More than 90 percent of cases are diagnosed in individuals over the age of 50. Both men and women are at risk for colorectal cancer. A family history of colorectal cancer or colorectal polyps increases the risk of developing colorectal cancer. Certain diseases of the bowels can increase the risk for colorectal cancer. Other risk factors include:
- Alcohol consumption
- Physical inactivity
- Diet high in fat and/or red meat
- Inadequate intake of fruits and vegetables
Early colorectal cancer usually causes no symptoms and can be detected by available colorectal cancer screening tests. However, as colorectal cancer progresses, the disease may become symptomatic. People with the following symptoms should see their doctor immediately:
- blood in or on the stool
- a change in bowel habits
- stools that are narrower than usual
- general stomach discomfort
- frequent gas or pains
- weight loss
- cramping or gnawing stomach pain
- decreased appetite
- weakness and fatigue
- jaundice (yellow-green skin color and white part of the eye)
If you have any of these symptoms, discuss them with your doctor. Only he or she can determine if they are caused by cancer.
Beginning at age 50, men and women who are at average risk for developing colorectal cancer, should have the following tests:
- Fecal Occult Blood Test (FOBT)--- a test that checks for blood in the stool. Foods and/or drugs can affect the test so check with your doctor at least one week before test for what should be avoided. Suggested test be done annually.
- Sigmoidoscopy --- an examination during which a trained doctor looks at the inside of the rectum and lower portion of the colon through a lighted tube. The doctor may collect samples of tissue or cells for closer examination. Suggested at least once every 5 years.
- Colonoscopy --- an examination during which a trained doctor looks at the inside of the entire colon through a flexible, lighted instrument called a colonoscope. The doctor may collect samples of tissue or cells for closer examination. Suggested once every 10 years.
- Double Contrast Barium Enema --- a procedure that involves X-rays of the lower intestines taken after a patient is given an enema containing a white dye, or barium, followed by an injection of air. The barium outlines the intestine on the x-ray film. Suggested once every 5 years.
- Surgery is the most common form of treatment for colorectal cancer. For cancers that have not spread, it frequently controls the disease.
- Chemotherapy, or chemotherapy with radiation treatment, is given before or after surgery to most patients whose cancer has spread into the bowel wall or to the lymph nodes.
- A permanent colostomy is very seldom needed for colorectal cancer and is frequently not required for colorectal cancer.
Check with your health insurance provider to determine your colorectal cancer screening benefits. If you are covered by Medicare, you now may be eligible to receive colorectal cancer screening benefits. For more information about Medicare, call the Health Care Financing Administration (HCFA) at 1-800-638-6833 or visit the Medicare website. You can also read our article on Medicare coverage of colorectal screenings for basic information.