Most colon cancers begin as small precancerous polyps (tissue growths that most often look like small, flat bumps or tiny mushroom-like stalks). These growths usually grow slowly and do not cause symptoms until they become large or cancerous.

Causes of Colon Cancer

Doctors aren’t certain what causes most colon cancers. In general, colon (colorectal) cancer begins when healthy cells in the colon develop changes (mutations) in their DNA. Healthy cells grow and divide in an orderly fashion to keep your body functioning normally. But when a cell’s DNA is damaged and becomes cancerous, cells continue to divide even when new cells aren’t needed. As the cells gather, they form a tumour.

Factors that may increase your risk of colon cancer include:

● Older age. Colon cancer can be diagnosed at any age, but the majority of people with colon cancer are older than 50 however doctors do not know why but the rates of colon cancer in people younger than 50 have been increasing.
● Black ethnicity. Black people have a greater risk of colon cancer than people of other races.
● A personal history of colorectal cancer or polyps. If you’ve already had colon cancer or noncancerous colon polyps, you have a greater risk of colon (colorectal) cancer in the future.
● Inflammatory intestinal conditions. Chronic inflammatory diseases of the bowel area, such as ulcerative colitis and Crohn’s disease, can increase your risk of colon cancer.
● Family history of colon cancer. You’re more likely to develop colon cancer if you have a blood relative who has had the disease and if more than one family member has/has had colon cancer, your risk is even greater.
● Low-fibre, high-fat diet. Colon (colorectal) cancer may be associated with a typical fatty diet that is low in fibre. There is an increased risk of colon cancer in people who eat diets high in red meat and processed meat.
● An inactive lifestyle. People who are inactive are more likely to develop colon cancer. Getting regular physical activity may reduce your risk of colon cancer.
● Diabetes. People with diabetes or insulin resistance have an increased risk of cancer.
● Obesity. People who are obese have an increased risk of dying of colon cancer when compared with people considered normal weight.
● Smoking. People who smoke may have an increased risk of colon (colorectal) cancer.
● Alcohol. Heavy drinking increases your risk of colon cancer.
● Radiation therapy for cancer. Radiation therapy directed at the abdomen to treat previous cancers increases the risk of colon cancer.

Symptoms of Colon Cancer

Even if you do not have a family history of colon (colorectal) cancer or polyps, tell your doctor if you have any of the signs that could indicate cancer, no matter what your age. Common signs of this type of cancer include the following:

● Constipation, diarrhoea, narrowing of stools, incomplete evacuation, and bowel incontinence – although usually symptoms of other, less serious problems
● By far the most noticeable of all the signs, blood on or in the stool can be associated with colon cancer. However, it does not necessarily indicate cancer, since numerous other problems can cause bleeding in the digestive tract, including haemorrhoids, anal tears (fissures), ulcerative colitis, and Crohn’s disease, to name only a few
● Anaemia – If you are anaemic, you may experience shortness of breath. You may also feel tired and sluggish, so much so that rest does not make you feel better
● Abdominal or pelvic pain or bloating
● Unexplained weight loss
● Vomiting

Prevention and Screening
Prevention

There’s no sure way to prevent colon cancer. But there are things you can do that might help lower your risk, such as changing the risk factors that you can control. You can take steps to reduce your risk of colon cancer by making changes in your everyday life. Steps you should take are:

Eat a variety of fruits, vegetables and whole grains.
Fruits, vegetables and whole grains contain vitamins, minerals, fibre and antioxidants, which play a role in cancer prevention.

Lower alcohol intake, or stop drinking.
If you choose to drink alcohol, limit the amount of alcohol you drink to a glass a day for women and two for men.

Stop smoking.
Speak to your physician about ways to quit smoking that’ll work for you.

Work towards a healthy routine.
Try to get at least 30 minutes of exercise on most days. If you’ve been inactive, start slowly and build up gradually. Talk to your doctor before starting any exercise programme.

Maintain a healthy weight.
If you are at a healthy weight, work to maintain your weight by combining a healthy diet with daily exercise. If you need to lose weight, ask your doctor about healthy ways to achieve your goal.

Screening

Colon (colorectal) cancer can be diagnosed by a variety of tests. This cancer type can be diagnosed after you show symptoms or if your doctor or nurse finds something during a screening test that is not normal.

Your doctor(s) may do the following tests:

● Blood tests (A complete blood count, tumour markers and liver enzymes)
● Imaging tests (X-rays, CT scan, MRI scan.)
● Biopsy
● Diagnostic colonoscopy (done after you show symptoms, not as a routine screening test)
● Proctoscopy

Early cancer detection often allows for more treatment options. Many people who have had colon cancer live normal lives. The treatments available today offer good outcomes, but you may require several treatments or a combination of treatments (surgery, chemotherapy, radiation) to have the best chance of avoiding a recurrence of the cancer. Remember to tell your doctor(s) about any changes in your health. This will help them decide if you need any additional screening tests or treatment.