The colon is also known as the large bowel or large intestine. The rectum is the last 10-15 inches of the colon. The outlet of the rectum is the anus, the opening through which bowel movements pass.
What is colorectal cancer?
Virtually every colorectal cancer begins as an adenomatous polyp, a small benign growth arising from the mucosa, or the lining of the colon or rectum. These polyps grow slowly, taking three to five years to even become visible without the use of a microscope. It takes even longer, possibly as much as ten more years, for a cancer to develop from a polyp.
Not all adenomatous polyps become cancers. But because there is no way to tell which will, virtually all are removed when diagnosed.
Polyps located in the colon and rectum share the same growth potential
What are the symptoms of colorectal cancer?
Often there are no symptoms in the early stages of colorectal cancer. Symptoms can include:
- Rectal bleeding;
- Blood in or on the stool after a bowel movement;
- Stools that are narrower than usual;
- Abdominal cramping or pain in the lower area of the stomach;
- Discomfort or urge to have a bowel movement when there is no need;
- Long bout of diarrhea, constipation or feeling the bowel does not empty completely;
- Weight loss for no apparent reason; or
- Frequent gas pains
- These symptoms can also be caused by other conditions. It is important to talk with your healthcare provider if you are experiencing any of these symptoms.
What are risk factors for colorectal cancer?
- Age – Most cases of colorectal cancer occur after the age of 50.
- Personal History – Having a personal history of colorectal cancer increases your risk for recurrence.
- Family history – Having a first-degree relative with colorectal cancer increases the risk for colorectal cancer.
- Familial colorectal cancer syndromes – Familial adenomatous polyposis (disease where hundreds of polyps develop usually occurring between ages 5-40) and hereditary nonpolyposis colon cancer (develops at a young age, but with only a few polyps developing). Both of these are genetic disorders.
- Chronic inflammatory bowel disease –
- Physical Inactivity
How can I decrease my risk of having colorectal cancer?
- Diet – A diet low in fat, high in fruits and vegetables, and high in fiber can reduce the risk of colorectal cancer. Avoid or limit alcohol consumption to no more than one drink a day.
- Physical Activity – Having a physical activity routine can help maintain a normal body weight and lower the risk of colorectal cancer.
- Smoking – Avoiding smoking can reduce the risk of colorectal cancer.
- Screening – Follow recommended screening guidelines. Finding polyps before they become cancerous, reduces the risk of colorectal cancer.
Are screening tests available?
What are screening guidelines?
Starting at age 50, those who are at average risk for colorectal cancer should have one of the five screenings every year:
- Fecal occult blood test (FOBT) or fecal immunochemical test (FIT) every year or;
- Flexible sigmoidoscopy every five years or;
- FOBT or FIT every year with a flexible sigmoidoscopy every five years or;
- Double-contract barium enema every five years or;
- Colonoscopy every 10 years.
Moderate risk are those who have a family history of colorectal cancer in a first degree relative or a personal history of polyps or colorectal cancer.
Colorectal cancer in first degree relative under age 55 or two first degree relatives:
- Colonoscopy at age 40 or 10 years before earliest case in the family, whichever is earlier.
Colorectal cancer in first degree relative over the age of 55:
- Colonoscopy at age 50 or 10 years before the age of the case or whichever is earlier.
Personal history of large or multiple polyps:
- Colonoscopy one year after removal of polyps. Every year if polyps recur or five years if normal.
Personal history of colorectal cancer:
- Colonoscopy one year after resection. Three years if normal, five years if still normal.
High risk are those with a hereditary or genetic disposition for colorectal cancer and those with inflammatory bowel disease.
Family history of Familial adenomatous polyposis:
- Flexible sigmoidoscopy and consideration for genetic counseling and testing beginning at age 12 to 14. Repeat sigmoidoscopy every one to two years.
Family history of hereditary nonpolyposis colon cancer:
- Colonoscopy and consideration for genetic counseling and testing beginning at age 21 to 40. Repeat colonoscopy every two years and then yearly at age 40.
Inflammatory bowel disease:
- Colonoscopy beginning at age 15 for left-sided colitis and age 8 for pancolitis. Repeat every one to two years.
The information provided are guidelines and not meant to be used as medical advice or replace the advice of your health care provider. It is important to discuss colorectal cancer with your health care provider