Overview – What is it?
Colorectal cancer is also referred to as bowel cancer. It can also be referred to as colon or rectal cancer depending on where it starts; either in the colon or rectum. This cancer occurs when malignant (cancerous) cells start to grow uncontrollably and rapidly in the inner lining of the colon or rectum. This occurrence can be caused by inherited gene mutation, inflammation of the colon, and personal or family history with colorectal cancer, among other factors.
The symptoms for this cancer include a change in bowel habits, blood in the stool and unintentional weight loss. It can be diagnosed using a stool DNA test, sigmoidoscopy, and a blood stool test, among other tests.
The treatment of colorectal cancer may be through surgery, chemotherapy and targeted therapy, among other treatment options, depending on several factors such as the stage of the cancer.
Preventing colorectal cancer can be done by getting regular screening and making other lifestyle changes such as eating healthy and not smoking.
Causes – What causes it?
The exact cause of colorectal cancer is not known, but there are some factors that are seen to increase the risk of developing this cancer including:
- Inflammatory bowel disease: People who suffer from IBD such as Crohn’s disease can develop chronic inflammation of the colon which increases the risk of getting colorectal cancer.
- Adenomatous polyps: Even though polyps are not cancerous, adenomatous polyps (adenomas) can develop into colorectal cancer with time.
- Inherited conditions: Certain rare inherited conditions such as lynch syndrome increase the risk of developing colorectal cancer.
- Family history: Having a close family member who has had colorectal cancer in the past can also increase your risk of getting the same cancer.
- Personal history: If you have had colorectal cancer before, the risk of it developing again is higher than a person who has not had this cancer. Women who have had ovarian or uterine cancer are also at a higher risk of developing colorectal cancer.
- Obesity: Being obese increases a person’s risk of developing this cancer.
- Lack of physical activity: Living an inactive life physically puts a person at a higher risk of getting colorectal cancer.
- Diet: Eating a lot of processed foods and red meat increases colorectal cancer risk.
- Smoking: People who smoke are also at a higher risk of getting this type of cancer.
- Age: The risk of colorectal cancer increases with age; adults above 50 years are at a higher risk of developing this cancer than young people.
- Gender: Men have a higher risk of developing colorectal cancer than women.
Symptoms – What do you feel?
The symptoms for colorectal cancer begin to show in the advanced stages and can resemble those of other non-cancer conditions such as haemorrhoids. It is, therefore, important to get tested if you get any of the symptoms below.
- Change in bowel habits
- Feeling that you haven’t emptied your bowel completely
- Presence of blood in the stool
- Stool that is narrower than normal
- Pain in the abdomen
- Unintentional weight loss
- Constant fatigue
Diagnosis – How do you diagnose it?
The type of test used in diagnosing colorectal cancer depends on the signs the person is having, the age and personal medical history as well as family history of the person concerned. The tests include:
- Physical examination: This takes place during the initial consultation when the doctor is able to understand a person’s medical history. A digital rectal exam is also done to check whether any bleeding is taking place from the rectum and to check if any other abnormalities can be identified.
- Foecal occult blood test: Used to check for presence of blood in the stool.
- Blood test: This test is used to check the number of red blood cells in the blood
- Stool DNA test: Used to analyse several DNA markers that colon cancer precancerous polys cells shed into the stool.
- Colonoscopy: This test allows a doctor to look inside the rectum and colon using a colonoscope which is a long flexible thin tube fitted with a camera.
- Sigmoidoscopy: A sigmoidoscope (which is not as long as a colonoscope) is used to examine the rectum and sigmoid (the last part of the colon) for any polyps.
- Biopsy: A sample of tissue is taken from the rectum and colon and examined under a microscope for any cancer cells.
- Imaging tests: This involves getting images of the internal organs by doing an ultrasound, x-ray, magnetic resonance imaging (MRI) scan, computerised tomography (CT) scan or positron emission tomography (PET) scan. The doctor is able to identify any abnormalities in the colon and rectum. An MRI gives more detailed images than other imaging tests.
Treatment – How do you treat it?
Treatment of this cancer is dependent on the age and medical history of the person, and the stage of the cancer. The treatment options for this cancer are as follows:
- entire organ in cases where the cancer is wide-spread. The different surgeries done for this cancer are:
- Colectomy: This is surgery done to remove part or all the colon where the cancer is present.
- Colostomy: This is done to create an artificial opening (stoma) in the lower abdomen to allow for elimination of waste from the body.
- Radiotherapy: Uses high-energy beams to kill or destroy cancer cells in the colon or rectum and prevent the cancer from spreading further.
- Chemotherapy: Uses a combination of anti-cancer drugs to kill cancer cells.
- Targeted therapy: This treatment option focuses on using drugs to target the specific cancer cells and destroy them without causing damage to normal cells.
Prevention – How do you prevent it?
The prevention of colorectal cancer focuses on reducing the risk factors for this cancer. This can be done by:
- Not smoking
- Limiting alcohol intake
- Eating a healthy diet rich in fruits, vegetables, fibre and less red and
- processed meat
- Remaining physically active
- Maintaining a healthy body weight
- Getting screened regularly
- Using aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs) to reduce the development of polyps in people who have had colorectal cancer or polyps before.