What is colorectal cancer?
Most colorectal cancers start in the cells that line the inside of the colon or the rectum. The colon and rectum make up the large intestine (large bowel). The large intestine is the last part of the digestive system. Organs of the digestive system change food into energy and help pass waste out of the body.
Food is digested in the stomach and the small intestine. As nutrients are removed from food, it changes into a watery mass. The watery mass passes through the small intestine into the colon. The colon absorbs the water and the semi-solid waste continues to travel to the rectum. This waste material is known as faeces or stool. The stool is stored in the rectum. When you have a bowel movement, the stool leaves the body through the anus.
Colorectal cancer usually grows slowly and in a predictable way. It is curable when diagnosed at an early stage.
What are the symptoms?
•Blood in the stool
•Change in bowel habits (going more often or less often than normal)
•Diarrhoea, constipation or feeling that the bowel does not empty completely
•Stools that are narrower than usual
•General discomfort in your stomach area (frequent gas pains, bloating, fullness or cramps)
•Weight loss for no known reason
•Feeling very tired all the time
•Vomiting
Often, these symptoms are not caused by colon cancer. Other health problems may be causing them. Talk to your doctor.
Colorectal cancer usually grows slowly and in a predictable way. It is curable when diagnosed at an early stage.
Causes of colorectal cancer
There is no single cause of colorectal cancer, but some factors appear to increase the risk of developing it:
Age — particularly after 50
Having polyps (small growths on the inner wall of the colon and rectum)
Family history of colorectal cancer — especially if the relative (parent, sibling, child) developed colorectal cancer before the age of 45
Having familial adenomatous polyposis (FAP) or hereditary nonpolyposis colon cancer (HNPCC)
Inflammatory bowel disease (ulcerative colitis or Crohn’s disease)
Diet high in red meat (beef, pork, lamb and goat)
Processed meat (ham, salami, sausage, hot dogs)
Alcohol consumption
Smoking
Physical inactivity
Obesity
Researchers are also looking at how diet affects the risk of developing colorectal cancer. A diet high in fibre seems to decrease risk, but more research is necessary to be sure.
Some people develop colorectal cancer without any of these risk factors
What you can do to cut your risk factors
Eat well: Keeping a healthy body weight keeps your colon healthy. You can do this by eating the right balance of food in healthy portions and by staying active. Make wise food choices by eating less red and processed meat, less saturated fat and salt, and more vegetables and fruit.
Be active: Even just 30 minutes a day of moderate physical activity helps a lot. It doesn’t have to be complicated. Go for a walk in the neighbourhood or the mall. Work in the yard. The more active you are, the more you reduce your risk of cancer.
Don’t smoke: There’s no doubt about it. Smoking is the single biggest cause of cancer. Be a non-smoker and avoid second-hand smoke. If you smoke, quit.
Cut down on alcohol: If you choose to drink, have only a moderate amount. Keep it to no more than one small drink a day for women and fewer than two small drinks a day for men. The more you cut down on alcohol, the more you reduce your risk of cancer. There is a limited risk if you drink a little.
Talk to your doctor: Your doctor is your partner for good health and a great source of information. Your doctor can help you understand what a healthy body weight is for you, quit smoking and decide what screening test is best for you
Get checked: Getting checked for colon cancer is the single most important thing you can do to prevent colon cancer. Make colon cancer screening part of your regular health routine. It could save your life.
Benefits and risks of screening for colorectal cancer
Almost every test or procedure has benefits and risks. It is important to be aware of them so that you can make an informed decision that is right for you.
No screening test is 100 per cent accurate, but a good screening test results in lower death rates in people with cancer.
Researchers also look for other benefits of screening including improved quality of life or less harmful treatments as a result of finding the cancer early.
Benefits of regular screening
Prevention and earlier detection of cancer: In most cases, the earlier a cancer is detected, the better your chance of survival. Research has shown that people who have regular stool tests are more likely to survive colorectal cancer. A faecal occult blood test (FOBT) or faecal immunochemical test (FIT) checks for hidden (occult) blood found in the stool. Polyps or tumours in the colon have blood vessels on their surface that can release a small amount of blood in the stool. Stool tests can prevent cancer by detecting polyps that can be removed before they become cancerous. Early detection may also mean less treatment and less time spent recovering.
— Health Canada
