8.NOV.2018 4 MIN READ | 4 MIN READ

Every day, approximately 5 Singaporeans are diagnosed with colorectal cancer.

A recent report by the Singapore Cancer Registry found colorectal cancer to be one of the 3 leading cancers diagnosed in Singapore, regardless of gender and ethnicity.

In fact, colorectal cancer is responsible for approximately 1 in 6 of all cancer diagnoses in Singaporean men and 1 in 7 in Singaporean women, with Chinese men and women being most at risk.

It’s more important than ever to know the facts about colorectal cancer. What is it? Why is it so common in Singapore? And what can you do to minimise your risks?

What is colorectal cancer?

Why is colorectal cancer common - Colorectal cancer
Colorectal cancer develops in the colon (large intestine) or rectum (the lower part of your large intestine, which stores stool).

Symptoms include:

  • Constipation
  • Diarrhoea
  • Changes in stool colour or shape
  • Blood in your stool
  • Bleeding from the rectum
  • Abdominal pain
  • Weakness and fatigue
  • Unexplained weight loss

However, in the early stages, many people do not experience any symptoms at all. In addition, some of these symptoms could be caused by other conditions, such as irritable bowel syndrome or Crohn’s disease. Don’t put off visiting your doctor if you are at all concerned – it’s important to get checked out for a proper diagnosis.

What causes colorectal cancer?

Sometimes, small, non-cancerous polyps grow in the lining of the large intestine. If these are found early, your doctor can usually remove them through simple surgery. Left untreated, there is a chance they could develop into colorectal cancer. Why these polyps develop in some people and not others is an area of medicine currently being researched by doctors.

In other cases, colorectal cancer develops for seemingly no reason at all, which is likely linked to a family history of the condition.

Your doctor can screen you to check for polyps or cancerous cells.

Am I at risk of colorectal cancer?

Why is colorectal cancer common - Risks
The risk of developing colorectal cancer increases over the age 50. Past this point, you should visit your doctor for regular bowel screening.

You’re also more likely to develop the condition if:

  • A family member has had colorectal cancer
  • You have a history of bowel diseases
  • You have a genetic syndrome (eg. familial adenomatous polyposis, which causes many small polyps to grow in the large intestine)

The incidence of colorectal cancer in younger patients is increasing, with roughly 1 in 10 Singaporeans who are diagnosed with the condition being under the age of 50. So don’t discount any symptoms based on your age – visit your doctor instead.

Why is colorectal cancer so common?

There are several reasons why colorectal cancer is becoming more common, not just in Singapore but around the world. People who are overweight, smoke, drink alcohol regularly, consume a high-fat diet, or don’t exercise are all at a higher risk of developing the condition. Type 2 diabetes is also a risk factor.

Unfortunately, in Singapore:

  • People are roughly 3kg heavier today than they were 15 years ago
  • Obesity rates are rising and could reach as high as 15% in the next 7 years
  • Smoking among people aged 18 – 29 has increased by 33%
  • The per capital alcohol consumption nearly trebled from 2005 to 2015, with 9.6% of people now regularly binge drinking
  • 59% of people eat more than their daily recommended calorie intake
  • Approximately 400,000 people are diabetic

The good news is that you can take control of your lifestyle to help minimise your risk of developing colorectal cancer as well as other life-threatening medical conditions. Here’s how:

Quit smoking

Why is colorectal cancer common - Quit smoking
Cigarette smoke contains carcinogens, which are well-known to cause cancer. In fact, 14 types of cancer are related to smoking. If you’re still struggling to squash the habit, it’s worth noting that quitting smoking will help to reduce your risk of not only cancer, but also chronic obstructive pulmonary disease, heart disease and diabetes.

Eat a balanced diet

Eating too much processed meat (like bacon, sausages and ham) and red meat (beef, lamb and pork) increases your risk of developing cancer. Instead, you should aim for a more balanced diet with plenty of fruits, vegetables and foods high in fibre. This should also help you to maintain a healthier weight and reduce your risk of obesity and diabetes.

And if all that’s not enough reason to change your habits, a balanced diet can also help to reduce your risk of high blood pressure, heart disease and stroke.

Cut down on alcohol consumption

Why is colorectal cancer common - Reduce alcohol consumption
Once in your system, alcohol turns into acetaldehyde, a toxic chemical that damages your DNA and stops your body from repairing the damage. It also triggers faster-growing cell development, which is more likely to cause the gene mutations that lead to cancerous growths.

No amount of alcohol is considered ‘safe’, so you’re better off cutting down your consumption as much as possible – the less you drink, the lower your risk.

Move more

Being active will help your body digest food quicker, meaning any nasty, cancer-causing chemicals will pass out of your body much faster. It also helps to reduce inflammation in your intestines and generally keep your body much fitter and healthier. Best of all, exercising regularly won’t just benefit your physical health, but also boost your energy and mood!

Still not sure where to start in improving your lifestyle? Consult your doctor for advice.


Article reviewed by Dr Chong Chee Keong, general surgeon at Parkway East Hospital


Alcohol Abuse Worse Among Young People. (2018, October 8). Retrieved 19 October 2018 from https://www.straitstimes.com/singapore/alcohol-abuse-worse-among-younger-people

Boh, S. (2017, October 16). Why Are Singaporeans So Prone to Diabetes? Retrieved 19 October 2018 from https://www.straitstimes.com/singapore/why-are-singaporeans-so-prone-to-diabetes-they-cant-produce-enough-insulin

Dr Wong Soong Kuan. Can Young People Get Colorectal Cancer? Retrieved 19 October 2018 from http://www.asiaone.com/health/can-young-people-get-colorectal-cancer

How Alcohol Causes Cancer. (2016, September 15). Retrieved 19 October 2018 from https://www.cancerresearchuk.org/about-cancer/causes-of-cancer/alcohol-and-cancer/how-alcohol-causes-cancer

Khalik, S. (2016, November 9). Colorectal Cancer Numbers Far Too High, Say Experts. Retrieved 19 October 2018 from https://www.straitstimes.com/singapore/health/colorectal-cancer-numbers-far-too-high-say-experts

Lai, L. (2017, June 20). Singapore Risks Hitting Obesity Rates of 15% in Seven Years. Retrieved 19 October 2018 from https://www.straitstimes.com/singapore/singapore-risks-hitting-obesity-rates-of-15-in-seven-years

Lai, L. (2017, July 10). Singaporeans Eating More Due to Busy Lifestyles. Retrieved 19 October 2018 from https://www.straitstimes.com/singapore/sporeans-eating-more-due-to-busy-lifestyles-food-variety-experts

Nelson, J. & Wint, C. (2018, July 31). Colorectal (Colon) Cancer. Retrieved 19 October 2018 from https://www.healthline.com/health/colon-cancer

Ng, E. A Look at Why Youths Smoke. Retrieved 19 October 2018 from http://www.asiaone.com/health/look-why-youths-smoke

Vroomen-Durning, M. (2009, May 20). Smoking Increases Colon Cancer Risk. Retrieved 19 October 2018 from https://www.everydayhealth.com/colon-cancer/smoking-and-colon-cancer-risk.aspx

What Are the Benefits of Physical Exercise? (2018, September 27). Retrieved 19 October 2018 from https://www.cancerresearchuk.org/about-cancer/causes-of-cancer/physical-activity-and-cancer/what-are-the-benefits-of-exercise

Chong Chee Keong
General Surgeon
Parkway East Hospital

Dr Chong Chee Keong is a general surgeon practising at Mount Elizabeth Novena Hospital and Parkway East Hospital, Singapore. He specialises in minimally invasive breast surgery, and the diagnosis and surgical management of breast cancer and colorectal cancer.