Colorectal cancer occurs when abnormal cells grow uncontrollably in the large bowel or rectum, forming a cancerous tumour.
Most colorectal cancers develop on the inner wall of the colon and rectum and usually start with growths called polyps.
These polyps are benign growths and usually harmless, however they can become cancerous if left undetected.
Colorectal cancer may also be called colon cancer or rectal cancer, depending on where the cancer is located and the area it originates from. Colorectal cancer is the most common cancer in Hong Kong and the second leading cause of death.1,2