Colorectal cancer (also known as colon cancer) is the most common cancer affecting Singaporean men and the second most common for women. It is primarily diagnosed in men in their 50s but cases have also been seen in younger men. Colorectal cancer may be prevented or successfully treated if discovered early.
In most people, colorectal cancer develops slowly over several years. It usually begins as a benign or non-cancerous polyp in the inner lining of the colon or rectum. A polyp may develop into cancer over time, but not all polyps turn into cancer.
We do not know the cause of colorectal cancer. However, there are some factors that increase your risk, such as:
- Family history of colorectal cancer (and an even higher risk if your family member was diagnosed with colorectal cancer before age 45)
- Being over 50-years-old
- Previous history of polyps
- History of ulcerative colitis or Crohn’s disease
- Smoking (which has been shown to increase polyp formation)
- A diet high in fats, red meats and low in fruits and vegetables
Signs and symptoms
Most cases of early colorectal cancer have hardly any symptoms, so they can be difficult to detect without regular screening.
In the later stages, common symptoms include:
- Change in bowel habits or texture and shape of stools
- Presence of blood in the stools
- Persistent abdominal discomfort or lump felt in abdomen
- Unexplained weight loss
- Unexplained anaemia
How can it be detected early?
The survival rate for colorectal cancer is as high as 90% if discovered in the early stage. Early detection is the best protection against colorectal cancer.
Some methods for screening are:
Faecal immunological stool test (FIT) or faecal occult blood test (FOBT)
- This is a simple test where a stool sample is collected, which is then sent to the lab to detect the presence of blood in the stool which cannot be seen by the naked eye
- If the results are positive, a colonoscopy will be needed
- This is the ‘gold standard’ for colorectal cancer screening
- Colonoscopy detects both precancerous lesions (such as polyps) as well as cancerous lesions and tumours
- This is recommended for men and women who have an average risk of colorectal cancer, do not show symptoms and are aged 50 and above
- Colonoscopy may be conducted earlier for anyone with a higher risk or symptoms
As with any disease, general guidelines for screening may differ for individuals based on their medical condition and risk factors. You will need to discuss this with your doctor to ensure that appropriate tests and screening are done for you.