« Colon Cancer Treatment & Prevention | Home | Three Stages Of Stress Response »
Facts About Colorectal Cancers
By peace | December 23, 2006
Cancer that originates in the colon or rectum may be called colon cancer, rectal cancer, or colorectal cancer. Colon cancer is the term most commonly used to refer to this type of cancer.
Almost all of the colorectal cancers begin with the growth of adenomas, a precancerous type of polyp that grows on the inside wall of the colon or rectum. In the early stage of growth, these polyps may not cause any symptoms. As they continue to grow into the intestine and beyond, symptoms such as rectal bleeding, a change in stools, blood in the stool, gas, bloating, abdominal fullness, or weight loss may be noticed. If these polyps are detected early through appropriate screening tests before they become cancerous, they can be removed and the development of colorectal cancer can be prevented.
Early detection and treatment have helped cut the death rate from colorectal cancer over the past 20 years. In fact, the 5-year survival rate for people with early-stage colorectal cancer is 90%; survival drops to 65% when the cancer has already spread to other parts of the body. Unfortunately, only about 37% of colorectal cancers are found before they have spread. Patients whose parents, siblings or children have colorectal cancer face an increased risk, as do women with a history of cancer of the ovaries or uterus. Colorectal cancer is also more common in patients who suffer from inflammatory bowel diseases such as ulcerative colitis or Crohn’s disease.
Although noncancerous polyps of the colon and rectum are relatively common in people over age 50, the presence of adenomas (precancerous polyps) increases the risk of colorectal cancer.
The majority of colorectal cancers are found in people over age 50. Polyps in the colon or rectum are slow-growing, and many are not cancerous; the polyp that can become cancerous is a special type known as an adenoma. In their early stages, polyps do not usually cause any symptoms, making it difficult to detect them. When symptoms do appear, they are typically changes in bowel movements. These symptoms may also be signs of other conditions, and may be ignored or not reported to the doctor.
Risk of Colorectal Cancer
There is no single cause of colorectal cancer, but some factors appear to increase the risk of developing it:
- age – particularly after 50
- polyps – small growths on the inner wall of the colon and rectum
- family history
- diet
- obesity
- physical inactivity
- heavy alcohol consumption
- living with inflammatory bowel disease (ulcerative colitis or Crohn’s disease)
- smoking
A family history of colorectal cancer in close relatives (parents, siblings or children) increases risk, especially if the relatives developed cancer before the age of 45. A condition that runs in families called Familial Adenomatous Polyposis (FAP) also increases risk. People in families with FAP or with a large number of colorectal cancer cases are often monitored closely so that cancer will be diagnosed early if it develops.
Researchers are also looking at how diet affects the risk of developing colorectal cancer. A diet high in vegetables and fruit is known to lower risk. A diet high in fibre and low in animal fats also seems to decrease risk, but more research is necessary to be sure.
Some people develop colorectal cancer without any of these risk factors.
Symptoms Of Colorectal Cancer
Colorectal cancer can be asymptomatic (i.e., it may not cause symptoms). Blood in the stool is a common sign of the disease. Blood may be bright red or dark in color, and may not be noticeable. Chronic bleeding may result in iron deficiency anemia, which may cause fatigue and pale skin.
Other symptoms include the following:
- Abdominal discomfort (e.g., pain, bloating, cramping, fullness)
- Change in bowel habits
- Constipation or diarrhea
- Narrow stools
- Nausea and vomiting
- Unexplained weight loss
- anemia (constant tiredness, shortness of breath)
- vague, dull pain or pressure that may spread to the back
Topics: All Posts, Diseases, Man's health, Woman's Health | No Comments »
