Risk factors of colorectal cancer

We don’t know what causes colorectal cancer or colon cancer, a deadly disease that will affect one in 20 men and one in 30 women in Singapore in their lifetime. Many risk factors have been established. For instance, if any member of your family has been diagnosed with colorectal cancer before the age of 45 years, you are considered at high risk.

Other non-modifiable risk factors for colorectal cancer include:

  • A history of familial adenomatous polyposis
  • Ulcerative colitis, a disease which tends to run in families
  • Two or three immediate relatives diagnosed with colorectal cancer at any age

However, that does not mean that most cases of colorectal cancer are hereditary in nature. “Less than 10 per cent of colorectal cancer cases are due to inherited gene defects,” says Dr Choo Su Pin, Senior Consultant at the Department of Medical Oncology, National Cancer Centre Singapore (NCCS), a member of the SingHealth​ group.

In other words, you can actually do something to reduce your colorectal cancer or colon cancer risk.

7 most effective lifestyle changes to lower your colorectal cancer risk

  1. Eat less fat and red meat. There is convincing evidence that red meat contributes to colorectal cancer risk. The World Cancer Research Fund recommends eating a maximum of 500g of cooked red meat per week.
  2. Eat more vegetables, fruits and fibre. Singapore’s Ministry of Health (MOH) recommends 5 or more servings of vegetables and fruits daily. Fibre helps to speed up the passage of food and dilute the carcinogens in the colon, according to the Singapore Cancer Society.
  3. Exercise regularly. You don’t even need to hit the gym every day. Just one hour of walking a week can reduce your colon cancer risk by up to a third, according to an American study that followed over 79,000 women between the ages of 40 and 65 for a period of 16 years.
  4. Quit smoking. Tobacco has been shown to increase polyp formation. Polyps are like bumps on the surface of the colon which can grow to be cancerous.
  5. Cut down on alcohol, especially distilled spirits. Having more than nine drinks a week of distilled spirits on a regular basis (for at least 10 years) can increase your colon cancer risk by more than 300 per cent.
  6. Control your diabetes. Diabetics are up to 40 per cent more likely to develop colon cancer than non-diabetics.
  7. Consider taking a calcium supplement. According to the World Cancer Research Fund, calcium “probably” has a protective effect against colorectal cancer. The evidence is derived from studies using calcium supplements at a dose of 1200 mg/day.

Colorectal cancer was featured in Health Xchange’s “Ask the Specialist” section. Check out the public’s questions and our specialist’s answers here.

Ref: U11​