COLO-RECTAL (Bowel) CANCER
 | Colorectal cancer is the most common non cutaneous cancer diagnosed in Australia. |
| Approximately 1 in 18 men and 1 in 26 women will contract the disease before the age of 75 years. Bowel cancer is uncommon before the age of 50 years, most commonly being diagnosed around 70. Risk increases with age and is greater in those with a family history of the disease. [prevention] [screening] [testing] [symptoms] [BACK to SCREENING]
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DIET
People's risk of developing colorectal cancer can be reduced if they :
| Restrict energy intake ( less than 2,500 kcal per day for men and 2,000 for women) |
| Reduce dietary fat ( less than 25 % of energy intake as fat) |
| Consume poorly soluble cereal fibres, such as wheat bran - especially if they are at high risk |
| Have a dietary calcium intake of 1,000 to 1,200 mg per day |
LIFESTYLE
The following healthy lifestyle factors may be protective :
| Participate in regular physical activity |
| Restrict alcohol intake |
| Do not smoke |
RECOMMENDED SCREENING, DEPENDING ON RISK LEVEL
The degree of risk falls into 3 categories - depending on family history.
CATEGORY 1 - Those at, or slightly above, "average" risk - approx. 98 % of the population.
Asymptomatic people fall into this category if :
| No personal history of colorectal cancer or ulcerative colitis and no confirmed family history of colorectal cancer, or |
| One first degree ( parent, sibling or child ) or second degree ( aunt, uncle, grandparent, niece, nephew or grandchild ) relative diagnosed with colorectal cancer at 55 years of age or older. |
SCREENING FOR CATEGORY 1 :
| Faecal occult blood test (FOBT) every 2 years |
| Consider sigmoidoscopy every 5 years from age 50 |
| Must see doctor if have symptoms. |
CATEGORY 2 - Those at moderately increased risk - this affects 1 to 2 % of the population.
Asymptomatic people fall into this category if :
| One first degree relative diagnosed with colorectal cancer before age 55, or |
| Two first or second degree relatives, on the same side of the family, diagnosed with colorectal cancer at any age. |
SCREENING FOR CATEGORY 2 :
| Colonoscopy every 5 years from age 50, or commencing 10 years younger than the age the cancer developed in the family member - whichever is earlier. |
| (Sigmoidoscopy + barium enema Xray is alternate to colonoscopy) |
| Consider FOBT in intervening years. |
CATEGORY 3 - Those at potentially high risk - this affects less than 1 % of the population.
Asymptomatic people fall into this category if :
| Three or more first or second degree relatives on the same side of the family diagnosed with colorectal cancer, or | ||||||
| Two or more first or second degree relatives on the same side of the family diagnosed with colorectal cancer and any of the following :
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| At least one first or second degree relative with colorectal cancer and multiple polyps throughout the bowel | ||||||
| Some body in the family has had a high risk mutation in the adenomatous polyposis coli, or has had a mismatch repair gene identified. |
SCREENING FOR CATEGORY 3 :
| These high risk families should be managed with the help of cancer genetic services |
| Screening will include colonoscopy every 1 to 2 years, commencing at around 25 years of age.
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FAECAL OCCULT BLOOD TESTING (FOBT)
Any manufacturers guidelines re special
preparatory diet etc. must be followed.
Patients should sample the surface of 3
separate stools. The motion should not come into contact with the water from the toilet
bowl.
There is also a national bowel screening program using the single ample "Insure" screening test.
All POSITIVE tests must be investigated by colonoscopy.
In 2011 the National
Bowel Cancer Screening Program published the results of patients referred for
colonoscopy after a positive test.
Approximately 4% had a definite or suspected bowel cancer and a further 10% had
polyps likely to become cancerous in the future.
Overall around 50% had some form of tumour or polyp (often minor).
SYMPTOMS of BOWEL CANCER
The most common presenting symptoms of bowel cancer are :
| Bleeding from the rectum - blood mixed with, or separate from the faeces |
| A change in bowel habit - especially a recent change |
| Symptoms of anaemia |
| Abdominal pain - especially of recent onset |
| Weight loss |
| Bloating |
These symptoms are not always clear cut and can have a variety of other causes, including much more common conditions such as haemorrhoids.