What is Colorectal Cancer?
Risk Factors
- Are over 50 years of age
- Have a family history of colon or rectum cancer
- Have a previous history of colon polyps
- Have a history of ulcerative colitis (ulcers in the lining of the large intestine) or Crohn’s disease
- Smoke or have a diet high in fats and low in fruits and vegetables
Colorectal Cancer Symptoms
- A change in bowel habits, including diarrhoea or constipation
- Presence of blood in stools
- Persistent abdominal discomfort such as cramps, gas or pain
Related: Signs and Symptoms of Colorectal Cancer
Colorectal Cancer Screening
Average-risk individuals:
i) are asymptomatic (no symptoms or signs)
ii) do not have a family history of colorectal cancer
iii) have a family history of colorectal cancer among non-first-degree relatives (i.e not parents or siblings) or relatives who got diagnosed older than 60 years old
If your doctor assesses your risk level to be increased or high, then he/she might suggest colorectal cancer screening via colonoscopy. Please refer to the table below for the screening frequency.
For individuals at increased risk or high risk, screening by colonoscopy is also indicated. Please refer to the table below
| Risk Group |
Onset (Age) | Frequency of colonoscopy screening |
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| i) Average Risk | ||||||
| 1. Asymptomatic or family history limited to non-first degree relatives |
50 years |
Every 5 to 10 years |
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|
ii) Increased Risk |
||||||
|
1. Colorectal cancer in first degree relative (parent, sibling) age 60 yrs or younger or two or more first degree relatives |
10 yrs prior to youngest case in the family or age 40 yrs, whichever is earlier |
Every 5 years |
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| 2. Colorectal cancer in first degree relative over the age of 60 yrs |
50 years |
Every 5 to 10 years |
||||
| 3. Personal history of colorectal polyps |
1 to 3 yrs after polypectomy in the presence of high risk features (>1cm, multiple, villous architecture); otherwise, 3 to 5 yrs after polypectomy for low risk polyps |
- |
||||
| 4. Personal history of colorectal malignancy |
One year after resection |
Every 1 to 3 years |
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| 5. Personal history of ovarian or endometrial cancer |
After resection |
- |
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| iii) High Risk |
||||||
| 1. Family history of familial adenomatous polyposis^ |
10 to 12 years (from puberty) |
Annually* |
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| 2. Family history of hereditary non-polyposis colorectal cancer (Lynch Syndrome )^ |
20 to 25 yrs |
Every 1 to 2 years |
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| 3. Inflammatory Bowel Disease |
|
|||||
a. Left-sided colitis |
From 15th yr of diagnosis |
Every 1 to 2 years |
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b. Pan-colitis |
From 8th yr of diagnosis |
Every 1 to 2 years |
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*Flexible sigmoidoscopy from age 10 to 12 years (puberty) until adenomas are identified, upon which screening is switched to colonoscopy
^Refer to Annex E for guidelines to refer suspected individuals for cancer genetic risk assessment.
The above colorectal screening information is taken from the Report of the Screening Test Review Committee.
Colonoscopy
Colonoscopy is one of the recommended screening tests for the average risk asymptomatic population, from age 50 years. For screening the general population at average risk, colonoscopy should be performed at an interval of no more than 5 to 10 years.
- Uses a flexible tube (colonoscope) to look at the inner lining of the large intestine (colon and rectum)
- Takes about 20 to 30 minutes to complete
- Has to be done in a hospital by a doctor trained in conducting colonoscopies
Discuss with your doctor which screening test is best for you.
For more information about your recommended screening for colorectal cancer, visit the Healthier SG Screening page.
Colorectal Cancer Treatment
- Colorectal surgery: this involves removal of the part of the colon that contains the cancer cells.
- Chemotherapy: chemotherapy can be used to destroy cancer cells after surgery, to control tumour growth or to relieve symptoms of colorectal cancer.
- Radiation therapy: radiation therapy uses X-rays to kill any cancer cells that might remain after surgery, to shrink large tumours before an operation so that they can be removed more easily, or to relieve symptoms of colorectal cancer. Side effects of radiation therapy may include:
- Diarrhoea
- Rectal bleeding
- Fatigue
Lower Your Colorectal Cancer Risk
- Eating plenty of fresh fruits, vegetables and whole grains which contain fibre and antioxidants
- Limiting fat intake especially saturated fat from animal sources such as fatty meat, red meat and full cream dairy products
- Limiting alcohol intake
- Quitting smoking
- Staying physically active and maintaining a healthy body weight
Contributed By
- Health Promotion Board