Colorectal cancer, or colon cancer, occurs in the colon or rectum. As the graphic below shows, the colon is part of the large intestine or large bowel. The rectum is the passageway that connects the colon to the anus.
Colon cancer, when discovered early, is highly treatable. Even if it spreads into nearby lymph nodes, surgical treatment followed by chemotherapy is highly effective. In the most difficult cases — when the cancer has spread to the liver, lungs or other sites — treatment can help make surgery an option for many, as well as prolonging and adding to one’s quality of life.
Research is constantly being done to learn more and provide hope for people no matter what stage they are. Most colon cancers develop first as polyps, which are abnormal growths inside the colon or rectum that may later become cancerous if not removed.
Stages of colon cancer
Stage 0: This is the earliest stage possible. Cancer hasn’t moved from where it started; it’s still restricted to the innermost lining of the colon. Stage 0 is also called Carcinoma in Situ.
Stage I: Cancer has begun to spread, but is still in the inner lining. Stage I is also called Dukes A colon cancer.
Stage II: Many of these cancers have grown through the wall of the colon and may extend into nearby tissue. They have not yet spread to the lymph nodes. Stage II is also called Dukes B colon cancer.
Stage III: Cancer has spread to lymph nodes, but has not been carried to distant parts of the body. Stage III is also called Dukes C colon cancer.
Stage IV: Cancer has been carried through the lymph system to distant parts of the body, most commonly lungs and liver. This is known as metastasis. Stage IV is also called Dukes D colon cancer.
- Blood in or on the stool (either bright red or very dark in colour)
- A persistent change in normal bowel habits such as diarrhea, constipation or both, for no apparent reason
- Frequent or constant cramps if they last for more than a few days
- Stools that are narrower than usual
- General stomach discomfort (bloating, fullness and/or cramps)
- Frequent gas pains
- A strong and continuing need to move your bowels, but with little stool
- A feeling that the bowel does not empty completely
- Weight loss for no known reason
- Constant tiredness
Note: Many people diagnosed with CRC never had any symptoms or early warning signs. Above are the most common signs of CRC, but it is important to note that the symptoms are not unique to CRC – check with your doctor if you suspect a problem.
Some risk factors
There is no “single cause” for developing CRC, but there some people who are considered to be at higher risk than the general population for CRC include:
Tips for cancer prevention
- Balanced diet (rich in fiber)
- Exercise daily
- Slim your waistline
- Know your family history
- Get screened: Starting at age 50, getting regular screening tests for colon cancer is the single best way to protect yourself. Colon cancer screenings help detect the disease in its earliest, most treatable stage.