Introduction
Colon cancer (also known as colorectal cancer) is the 2nd commonest cancer in Malaysia. It accounted for 14.1% of all cancers diagnosed in Malaysia for the period of 2017-2021, ranking 2nd behind breast cancer. Colon cancer is the commonest cancer in men, and 2nd commonest in women.
75% of patients with colon cancer are already at stage III or IV when they are diagnosed. Early stage colon cancer frequently has NO symptoms.
Certain factors increase the risk for getting colon cancer, for example:
- Family history of colon cancer
- Certain conditions such as acromegaly and ulcerative colitis
- Obesity
What can be done?
The good news is that colon cancer is preventable. Polyps in the colon are the precursor lesions to cancer, and take 5-10 years to develop from a simple polyp into colon cancer.
Detecting and removing colon polyps are the key to preventing colon cancer. This forms the basis of colon cancer screening. No colon polyps, no colon cancer. It’s that simple. Periodic screening will help to ensure this. Once you start screening, just repeat it every 5-10 years. My personal practice is to recommend 5-yearly colonoscopy intervals.
In general, patients can consider starting screening from the age of 45, although one should start earlier if there is a strong family history of colon cancer.
Always remember, there is a difference between screening and investigating.
Screening is for patients who have no symptoms.
If you do have symptoms, you need investigating now, not wait until the age of 40 or 45 for screening.
Screening methods
1. Stool test kit
This tests for the presence of blood in your stools.
Similar to a Covid test kit, this can be done in the comfort of your own home. This test kit is available over-the-counter at the major pharmacies.
If it’s positive, you will need a colonoscopy. If it’s negative, congratulations! You can repeat the test after 1 year.
Remember, the stool test kit is only for people without a family history of colon cancer. If you do have a family history of colon cancer, you must go straight to a colonoscopy, and not a stool test kit.
The advantage of the stool test kit is that it is non-invasive, cheap, and can be done in the comfort of your own home. Just know that apart from colon cancer or colon polyps, there are other causes of a positive test kit result, such as:
- haemorrhoids
- nosebleeds
- stomach ulcer
- inflammatory bowel disease
2. Colonoscopy
A thin, flexible camera is inserted through your back passage (anus), enabling a thorough examination of your colon. A quick and painless procedure, it allows the doctor to detect polyps and immediately remove them.
The advantage of colonoscopy over the stool test kit is that, during a colonoscopy, if any polyps are detected, it can be removed on the spot. Another advantage is that a colonoscopy is a one-step test, whilst the stool test kit is a two-step test (if the kit is positive, you have to move on to a colonoscopy to complete the screening process).
In the field of Gastroenterology, we have a saying, “The best screening test is the one that the patient does”. No matter which one you choose, as long as you do it and complete it, you will make me a happy person, knowing that somewhere, somebody has already done their colon cancer screening.
Lifestyle Advice
We all can make changes to reduce our risk of getting colon cancer. These include:
- Reduce intake of ultra-processed and sugary foods and drinks
- Reduce intake of red meat
- Increase intake of fruits and vegetables
- Maintain a healthy bodyweight
- Regular exercise
- Stop smoking
- Avoid alcohol
- Undergo regular screening
