Singapore Medical Guide | Singapore Healthcare

Colorectal cancer is currently the most common cancer in Singapore men and women. It has increased in incidence over the past 5 years at an alarming rate. The cause of colorectal cancer is well documented. Majority of these arise from polyps or growths in the lining (mucosa) of the large intestine. These take between 3-5 years to become cancerous. Thus, if these polyps are detected early and removed, colorectal cancer can actually be prevented.

Screening in colorectal cancer is to detect the presence of polyp or cancers at an early stage to allow for early treatment and a better chance at cure. So should everyone go for screening? At what age should we start screening? Are there any risks involved?

Am I at risk of colorectal cancer?

According to most experts, colorectal cancer arises sporadically (in those with no family history) in 80% of cases. Fifteen percent may have an immediate family member with a history of colorectal cancer and only 5% will have a family cancer syndrome (such as Familial Adenomatous Polyposis or Hereditary Non-polyposis Colorectal Cancer).

The following table illustrates the average risk of being diagnosed with colorectal cancer:

 No risk factor      2%
 1 family member with colorectal cancer  6%
 1 family member <45y with colorectal cancer 10%
 2 family members     20%
 3 family members     50%

The Ministry of Health has published guidelines on who should be screened (2003). It has recommended that those aged 50 years and above with no symptoms should go for screening. If you have an immediate family member with colorectal cancer diagnosed before the age for 50 years, then you should go for screening 10 years before that age of diagnosis. For example, if your father had colorectal cancer at age 45 years, you should be getting a colonoscopy at 35 years.

Similarly, if you have any symptoms of rectal bleeding, blood in stools, abdominal pain for more than 2 weeks, change in bowel habits for more than 2 weeks, or sensation of incomplete evacuation of bowel, then you should be seeking a medical opinion and going for a diagnostic colonoscopy.

Remember, picking up colorectal cancer at an early stage improves your survival. All early cancers have no symptoms, hence the importance of screening. By the time any symptoms appear, the cancer may already be in a late stage. So get screened early.

The risks involved in a diagnostic colonoscopy are minimal. The chances of perforation or “bursting” of the colon is 0.1% or 1 in a 1000 in experienced hands. Other risks including heart attack, stroke, aspiration or breathing difficulties as a result of sedation are even rarer. This must be balanced by the advantage of early detection of colorectal cancer and the higher chance of cure.

So if you are above the age of 50 years, or have any gastrointestinal symptoms – Get Screened!