Causes and risk of Colorectal cancer

Dear Readers,

Angella M. is a 52-year-old woman who is curious and concerned about what causes colon cancer, and how to protect herself against developing this illness. Her elderly uncle is being treated for this disease. Her grandfather died from colon cancer many years ago. Her cousin also died from colon cancer several years ago after a prolonged illness which began with the biopsy of a colonic polyp. Angella has been avoiding all cancer-screening tests for many years but now feels very vulnerable since she is very close to her uncle. She wants to know more about this illness which seems to have targeted her family.

Colorectal cancer is a major source of cancer death throughout the world. Colorectal cancers have both genetic and environmental components. It is thought that a mutation in the genes which are associated with colorectal cancer has caused the colonic tissues in some individuals to be susceptible to cancer change.

Environmental factors are often present which drive the change for essentially normal colorectal cells to become cancerous cells. Colorectal cancer often begins as a polyp in the intestinal colon and rectal tissues. This polyp gradually transforms into cancer.

Environmental factors

Environmental factors which affect colorectal cancer are often associated with the person's diet. These include:-

High dietary fat consumption

Low dietary fibre intake

Excessive alcohol consumption

Obesity

These conditions are risk factors for colorectal cancer. Also of interest is that an increase in selenium, through dietary intake or mineral supplements, is associated with a decreased risk of colorectal cancer.

When diagnosed early, colorectal cancer can be cured by surgery but, unfortunately, the cancer is mostly without symptoms at this point. The right side of the colon especially, is large and tumours can grow to quite a large size before any obstruction to the passage of stool occurs to cause symptoms. Blood loss in the stool, due to the cancer, can lead to anaemia.

Some presenting symptoms of colorectal cancer are:

Constipation

Change in bowel habits

Anaemia

Fatigue

Palpitations

Weight loss

The colonoscopy procedure which visually examines the intestinal colon, from the anus to the area known as the caecum, is the single test which results in detection of 90 to 95 per cent of tumours in the colon. Endoscopic ultra sound is also useful in the detection of colorectal cancer, as is the abdominal CT scan, but the ability of these two latter tests to discern early cancer is poor. They are useful in determining if cancer has spread.

Measuring Carcino Embryonic Antigen (CEA) protein in the blood is a good means of following up on the course of colorectal cancers. CEA is produced in over 90 per cent of colorectal cancers. This test is readily available at local medical laboratories and can be requested by any physician.

treatment

Chemotherapy is also used in the treatment of colorectal cancer but only a small number of persons really benefit from this treatment .Those cured by surgery really don't need chemotherapy and then some people don't respond to the chemotherapy. However, as these persons are not readily distinguishable, the chemotherapy is still offered to a relatively large group.

For some people, chemotherapy can cause really adverse effects and decrease the quality of life. Still, choices always have to be made at some point. The real issue is duration of life versus quality of life.

Any individual past adolescence, with a family history of colorectal cancer, should be screened for this disease by colonoscopy at least every three years or sooner.

Write to: Lifeline

PO Box 1731

KGN 8

Causes & risk of

Colorectal

cancer

Anthony Minott

Nurse Barnaby (right) from Apex Medical checks the blood pressure of COK Sodality Co-operative Credit Union Ltd's Gillian Gordon during a Fair and Expo at Independence City Primary School in Portmore, St Catherine recently.