Colorectal cancer may be very prevalent but can be treated or even cured when detected early.

Colon cancer is cancer of the large intestine (colon), the lower part of the digestive system. Rectal cancer is cancer within the rectum, which forms the last several inches of the colon. Together, they’re often referred to as colorectal cancer. While all cancers are best treated as early as possible, this is especially important in rectal cancer as it often presents late. Symptoms are very similar to those of benign anal diseases like piles and constipation and are often ignored until it is too late. However, there is hope yet; the earliest stage rectal cancers will not have spread outside the innermost lining of the rectum and can be contained and treated. Therefore the earlier the stage, the better the chances of survival for the patient.

Who’s at risk?

Risk factors for rectal cancer are the same as risk factors for colon cancer. These include a family history of colorectal cancer, and a history of colorectal polyps and inflammatory bowel diseases (IBDs) like ulcerative colitis and Crohn’s disease.

The second important factor in prognosis is the grade of the cancer, which indicates the speed of the tumour’s spread and growth. Tumour cells that resemble normal cells spread slower than those that do not.

What are the symptoms?

The colorectum is a tubular conduit that allows the passage of faeces from inlet to outlet. Since much of the colonic contents are fluid (typically, faeces only becomes semi-solid or solid at the level of the descending colon), symptoms of obstruction and blockage to flow may not be present until the growth is very large and almost or entirely blocking the colonic tube.

The symptoms relate mainly to intestinal obstruction, such as abdominal cramps when the faeces squeeze through the increasingly narrow colonic tube. Other symptoms include intestinal bloating and unexplained fluctuation of stool frequency.

When and how often to be screened?

Most colorectal cancers start life as small benign polyps or growths. These polyps remain in the body for as long as 10 or 20 years, growing insidiously before turning malignant at some stage. If they are removed at any stage before this happens, the patient can be rendered cancer-free.

This means that if you have concerns about the state of your bowel, you should have your first screening when you are 35-40 years of age. If no abnormality is found, you can schedule screenings by colonoscopy within 5-10 years. A colonoscopy is one of the more extensive types of screening available. This non-invasive test uses a tool called a colonoscope to examine the colon and rectum. The entire procedure can be completed within an hour, and the patient is expected to fast for at least one day prior to the test.

Patients with a family history of colorectal cancer should be screened at least 10 years earlier than the age of the youngest affected member of the family, and at closer intervals.

The bottom line? It is much better to have a benign polyp removed early regardless of size, than to delay and risk having it develop into a cancer that could have been prevented. This applies especially to those at higher risk because of a family history of cancer or a history of colorectal polyps and IBDs.