What is bowel cancer and how does it develop?
Bowel cancer develops silently, without any symptoms, in the inner lining of the large intestine. Mutation of the cells in this inner lining lead to the development of one or more polyps. Over time, polyps grow in size and can eventually become cancerous or malignant. Left untreated, a malignant polyp will gradually invade the bowel wall and other nearby structures. Cancerous cells can enter the blood vessels and lymphatic system and travel to distant organs such as the liver and lungs where secondary cancers develop.
- Bowel cancer is the second most common cancer in Australia
- One in thirteen people in NSW develop bowel cancer at some stage in their lives
- Bowel cancer can be diagnosed early (pre symptoms), and over 90% of these early cases are curable
- About 60% of newly diagnosed bowel cancer patients are in the advanced stages of the disease and this is when prognosis is poor
- Currently, only 38% of eligible people are electing to be screened for bowel cancer
- Early stages can have no symptoms
- Abdominal pain
- Weight loss
- Iron deficiency
How can you be tested for bowel cancer?
If you don’t have a family history of polyps or bowel cancer and you’re not experiencing symptoms such as abdominal pain, weight loss, iron deficiency or bleeding from the bowel, a stool test called a fecal occult blood test (FOBT), which tests for the presence of blood in the bowel, is probably the best starting point. The test must be done on three stool samples and if any of the three samples tested are positive to the presence of blood, a colonoscopy is needed.
For males, approximately 50% of positive FOBT tests indicate the presence of one or more polyps. This is the case for 35% of females over the age of 50. Only 1% of people whose FOBT result is positive may have a cancer. Cancers detected from a FOBT screen are usually in the early stages and have a good prognosis/are treatable.
If an advanced polyp or cancer is diagnosed, patients are guided through the management options.
For patients with a family history of polyps or bowel cancer, your GP will probably refer you for a colonoscopy without an FOBT.
What does a colonoscopy involve?
A colonoscopy involves the use of a tiny camera to examine the large intestine/bowel. The procedure is conducted under anaesthetic and is painless.
Before the colonoscopy, the patient is guided through some relatively simple preparations to ensure a clear result.
If you have a family history of bowel cancer or polyps, you should have a colonoscopy at age 50 and continue with a follow-up colonoscopy every five years. If your family history involves a family member who was diagnosed with bowel cancer before they turned 60, you should have a colonoscopy when you are ten years younger than the age they were when they were diagnosed. For example if the family member was diagnosed at 50 years of age, your screening should start at 40 years of age.
More frequent screening is recommended if you have a suspected hereditary bowel cancer syndrome such as lynch syndrome or familial adenomatous polyposis.
Locally, colonoscopies are conducted at Mayo Private, Forster Private or the Manning Hospital. Ask your GP for a referral or visit gastroliverclinic.com.au for more information.
On turning 50, everyone in Australia is sent a bowel screening test kit. Please follow the instructions or make an appointment to talk to your GP if you are unsure how to do the test or have any concerns.
Sadly only 38% of eligible people are doing the routine bowel cancer screening. Routine FOBTs or colonoscopies (if suggested by your doctor) can save your life.
Dr Senanayake Prematilake,Gastroenterologist, Gastrointestinal and Liver Clinic, Taree performs gastroscopy and colonoscopy procedures at Mayo Private Hospital and Forster Private Hospital.