Colorectal cancer is said to occur when cells in the colon or rectum grow in an uncontrolled manner. Colon is a part of the large intestine while rectum connects colon to the anus. Both male and females can get affected by this cancer, especially those above the age of 45 years. Early screening for colorectal cancer can prevent deaths as colorectal cancer is more treatable in its early stages.

Symptoms of colorectal cancer

Colorectal cancer does not show visible signs and symptoms in its early stages. So, someone could be suffering from colorectal cancer and be completely unaware of it. In general, colorectal cancer symptoms may include:

• Changes in bowel habits
• Blood in stool
• Abdominal pain and cramps that doesn’t go away
• Unexplained weight loss
• Fatigue

If you notice any of these symptoms, you should immediately consult your healthcare provider.

Why is screening for colorectal cancer important?

The presence of polyps in the colon or rectum marks the beginning of colorectal cancer. Polyps are growths that shouldn’t normally be present. With the passing of time, some of these polyps can turn cancerous.

Screening is important to find out if these polyps are present in the colon or rectum and to remove them early, before they turn cancerous. Also, screening helps in starting early treatment for colorectal cancer because it works best in early stages. Thus, screening identifies problem even before the symptoms appear.

Risk factors for colorectal cancer 

An individual who is 45 years of age or above is at greater risk of developing colorectal cancer. Incidentally, the risk of colorectal cancer increases, if:

• You or your close relative has had colorectal polyps or colorectal cancer.
• You suffer from inflammatory bowel disease (IBD), Crohn’s disease, or ulcerative colitis.
• You have a genetic syndrome e.g. familial adenomatous polyposis (FAP) or hereditary non-polyposis colorectal cancer (Lynch syndrome).

Types of colorectal cancer screening tests 

There are several screening tests to help identify polyps or colorectal cancer. Some of them are given below:

A. Stool tests
• Guaiac-based Fecal Occult Blood Test (gFOBT): Makes use of the chemical, guaiac to detect the presence of blood in a sample of stool.
• Fecal Immunochemical Test (FIT): Using a test kit, antibodies help to detect blood in the stool sample.
• FIT-DNA Test (or Stool DNA test): For this test, entire bowel movement is required to detect altered DNA in the stool.

B. Flexible Sigmoidoscopy (Flex Sig): In this procedure, a thin, short, flexible lighted tube is inserted inside the rectum to check for the presence of polyps or cancer inside the rectum and lower third region of the colon.

C. Colonoscopy: It uses a similar thin but longer, flexible lighted tube to reach inside the rectum and entire colon to look for polyps or cancer in these areas. During the procedure itself, most polyps and some cancer can be removed. This test is usually done as a follow-up if other screening tests detect something unusual.

D. CT Colonography (Virtual Colonoscopy): Computed Tomography Colonography makes use of X-rays and computers to get a complete view of the entire colon. The images produced are analyzed on a computer screen by the healthcare provider.

To guard against colorectal cancer, once you turn 45 years or above, it is best to undergo regular cancer screenings. Your healthcare provider will usually recommend which screening tests to undergo. It is important to understand that it is easier to detect colorectal cancers in the starting stages, making screening essential.