Colorectal cancer starts as a growth on the inner lining of the colon or rectum. These growths are called polyps and some types of polyps can change into cancer over time. If some types of polyps are not removed, there is a chance they may eventually become malignant tumors and become colorectal cancer. Therefore, early detection and removal of colorectal polyps are the most important ways to prevent colorectal cancer.

Colorectal cancer is the second commonest cancer in Hong Kong. With the changing dietary habits and lifestyles of modern individuals, there has been an increasing trend in occurrence among the younger generation in recent years. In 2021, there were 5,899 new cases, contributing about 15.3% of all new cancer cases in Hong Kong and 2,298 people died from Colorectal cancer, accounting for 15.2% of all cancer deaths.

Most patients, especially young patients, have low awareness in prevention of colorectal cancer, often missed the golden opportunity for receiving treatment. At the same time, the Hong Kong Cancer Information Center online resources also indicate that Colorectal cancer, if detected and treated early, is highly curable. The 5-year relative survival rate for stage 1 colorectal cancer is over 95%, whereas the 5-year relative survival rate for stage 4 colorectal cancer is less than 10%.

Colorectal cancer stage and 5-year relative survival rate are as follows:

Understanding the causes and symptoms of colorectal cancer, getting regular check-ups, can help find colorectal cancer at an early stage, when treatment is most likely to be successful.

Colorectal Cancer Risk Factors:

• High intake of animal fats, red meat, processed meat, and low fiber (such as fruits and vegetables) in the diet.
• Lack of exercise, obesity, alcohol consumption, or smoking.
• Family history of colorectal cancer or hereditary colon disease.
• Chronic inflammation of the colon (such as ulcerative colitis) or colon polyps.

Symptoms of Colorectal Cancer is:

• Hematochezia: blood in the stool (black or dark red) or the presence of a significant amount of mucus.
• Unexplained changes in bowel habits, such as persistent diarrhea or constipation; stool shape changes (such as becoming thinner)
• Tenesmus: a feeling of unable to empty the bowel.
• Persistent abdominal discomfort, such as bloating or cramping.
• Unexplained and unintentional weight loss.

If you have the above symptoms, please consult a doctor as soon as possible and arrange for a colonoscopy examination.

*Information from Hong Kong Cancer Online Resource Hub, Hong Kong Cancer Registry