Colorectal cancer is a type of cancer that starts in the colon or rectum. The large intestine or colon, is the final part of the digestive tract. It is responsible for absorbing water from the food that we eat and turning indigestible food into waste.
Colon cancer and rectal cancer are often grouped together and known as colorectal cancer, due to their common features. Nearly all colorectal cancers begin as polyps, which are benign growths on the inner lining of the colon or rectum. Over time, some of these polyps can change and become cancerous. Polyps may be small and generally do not cause any symptoms.
Some colorectal cancers arise from the innermost lining of the colon or rectum without the development of polyps. Cancer cells can grow deep into the wall of the colon or rectum and may extend into the fatty tissue that surrounds the colon and rectum. Colorectal cancer can also spread to nearby lymph nodes. In some cases, cancer cells spread through blood vessels to other parts of the body such as the liver.
Colorectal cancer is the most common cancer in Singapore, affecting approximately 45 out of every 100,000 people here. For men, it is the second most common type of cancer and for women it comes second after breast cancer. During a period of five years, between 2017-2021, 12,239 cases of colorectal cancer were diagnosed in Singapore.
Colorectal cancer is most commonly diagnosed in people aged 50 years and above. However, colorectal incidence is also rising amongst younger individuals under the age of 50.
Younger individuals who are diagnosed with colorectal cancer may have hereditary conditions including familial adenomatous polyposis (FAP)or hereditary non-polyposis colorectal cancer. There may also be sporadic (non-hereditary) cases of young colorectal cancer.
Regular screening tests are recommended to help prevent colon cancer by identifying and removing polyps before they turn into cancer.
