Colorectal cancer, also known as colon cancer, rectal cancer or bowel cancer, is cancer of the colon (the longest part of the large intestine) or rectum (the last several inches of the large intestine before the anus). Colorectal cancers are mostly adenocarcinomas (cancers that begin in cells that produce mucus and other fluids).
Colorectal cancer is the most common cancer in Singapore1. The incidence of this cancer has been steadily increasing in both men and women. Singapore has one of the highest incidence of this cancer in Asia, together with Taiwan, Japan and Australia. Thankfully, the number of deaths from colorectal cancer has been dropping for the last 15 years due to more people going for regular screening which can help detect colorectal cancers early. Treatment for colorectal cancer has also improved, allowing for patients to be treated more effectively if the cancer is detected early.
Singapore Cancer Registry Interim Annual Report, Trends in Cancer Incidence in Singapore, 2010-2014, National Registry of Diseases Office (released 26 May 2015)
There is no single cause of colorectal cancer, as in most cases, colon cancer begins as a polyp that develops into a cancerous growth. People with certain risk factors are more likely to develop colorectal cancer. The common risk factors for colorectal cancer are:
1. Colorectal Polyps
These are growths on the inner wall of the colon or rectum commonly found in people over the age of 50. While most polyps are benign (not cancer), some polyps (adenomas) can become cancerous.
2. Ulcerative Colitis or Crohn’s Disease
A condition that causes inflammation of the colon, such as ulcerative colitis or Crohn’s disease, over many years can increase the risk of developing colorectal cancer.
3. Personal History of Cancer
A colorectal cancer survivor may develop colorectal cancer a second time. Women with a history of cancer of the ovary, uterus or breast are also at a higher risk of developing colorectal cancer.
4. Family History of Colorectal Cancer
A family history of colorectal cancer can indicate a higher risk of developing this disease, especially if a family member or relative suffered from the cancer at a young age.
5. Lifestyle Factors
People who smoke, or consume a diet that is high in fat and low in fruits and vegetables have a higher chance of developing colorectal cancer.
6. Age over 50
Colorectal cancer is more likely to occur to people over the age of 50. More than 90% of people with this disease are over the age of 50.