Colorectal cancer is a major public health problem and a leading cause of cancer mortality in the western world. In Malaysia, it is now emerging as the second and third commonest cause of cancer in both males and females respectively. Ethnic variation is also observed with the disease being most common amongst the Chinese.
Environmental factors and genetics play varying roles in the aetiology of colorectal cancer. About 80% of colorectal cancers arise sporadically with no evidence of genetic susceptibility. In the remaining cases, genetic factors play a significant role. Hereditary forms of colorectal cancer are distinguished by the presence or absence of polyposis. The polyposis types are characterized by multiple colorectal polyps. Colorectal cancer, or colon cancer, is curable 90% of the time when detected and treated early. However, by the time the patient presents to the physician with symptoms, the cancer is frequently advanced with little hope of cure.
As the survival following surgical resection of the early cancers is excellent, the best present strategy for cure of colorectal cancer is to detect these early lesions, preferably prior to the development of any symptoms
Amongst the symptoms to look for are:
- Unexplained change in bowel habits.
- Chronic diarrhea or constipation.
- Blood in the stool.
- A feeling that your bowel doesn't empty completely.
- Persistent abdominal pain.
- Unexpected or sudden weight loss.
- Chronic tiredness or unexplained fatigue.
There is now evidence to suggest that screening asymptomatic populations can reduce the mortality as a result of colorectal cancer by early detection as well as prevention by polypectomy of colonic polyps. A colon polyp is a small clump of cells that forms on the lining of the colon. Most of these polyps are benign, harmless and usually do not cause any symptoms. But over time, some of these colon polyps can develop into colon cancer, which is often fatal when found in its later stages. There are also several risk factors that increase the risk of colorectal polyps and colorectal cancer. These include:
- Age 50 or older.
- Have a family or personal history of colorectal cancer or polyps.
- Have a personal history of inflammatory bowel disease
- Are a smoker.
- Are obese or physically inactive.
- Eat a diet high in saturated fat or red meat.
A colonoscopy is the endoscopic examination of the colon and the distal part of the small bowel with a fiber optic camera on a flexible tube passed through the anus. A colonoscopy helps find ulcers, polyps, tumors, and areas of inflammation or bleeding. Colonoscopy is able to detect up to 95% colorectal cancer and allows polyps to be biopsied and removed and is currently recommended as the initial screening test for high risk individuals as listed above.
Therefore, any individuals with the above risk factors should come and make an appointment for screening colonoscopy. A colonoscopy only takes 30 minutes and is able to detect small polyps and remove them before they grow and become cancerous. It's important to have regular screening tests, such as colonoscopy, because colon polyps found in the early stages can usually be removed safely and completely. The best prevention for colon cancer is regular screening for polyps.