Colon cancer is said to be the third most common cancer in the world, and is named as the second leading cause of death due to cancer. This form of cancer, also referred to as colorectal cancer, has no visible symptoms in the early stages of its growth, making regular screening for pre-cancerous growths in the colon vital for the cancer’s early detection.

Understanding Colon Cancer Better

Colorectal cancer develops when pre-cancerous polyps or abnormal growths form in the colon or rectum. Abnormal cell growth during the regular replacement of cells in the lining of the colon turns into polyps when left unchecked, although it may take up to 10-15 years for these polyps to become cancerous. Once the polyps turn cancerous, the cancer can spread to nearby organs as well as throughout the body. This form of cancer is highly treatable if detected early, highlighting the need for screening. The survival rates before the cancer spreads are close to 90 percent however, once it spreads the survival rate drops dramatically.

Why does screening help?

During the initial stages of the cancer there are often no symptoms. It is only in the later stages of the cancer development that symptoms such as rectal bleeding, abdominal pain or discomfort and changes in bowel movements appear. This is why doctors suggest regular screening even when there are no symptoms. By screening at regular intervals the polyps are spotted well before they turn cancerous, enabling appropriate and timely treatment.

Screening is strongly recommended for those above the age of 50 or those having familial history of colon cancer. Other cases requiring screening are those people suffering from inflammatory bowel diseases as well as those having lifestyle issues such as improper diet and obesity.

Types of Screening Tests

There are numerous effective screening tests for colon cancer available today that are quick, safe and involve very little discomfort.

Colonoscopy is the most preferred test to screen for colon cancer. In colonoscopy, a thin, flexible tube with a camera and light is inserted through the rectum to check for polyps inside the entire colon and the rectum. In case any growth is found, the doctor can remove it right away using special instruments. This screening test is recommended to be conducted once in every 10 years.

Sigmoidoscopy is another form of screening where a lighted thin tube is inserted to examine the end portion of the rectum and the colon for any abnormality and remove it if present. This type of test is recommended to be done every 5 years. In both cases, if abnormal polyps are found, it is biopsied for diagnosing cancer.

These tests are outpatient procedures which would take a few hours to be completed with the actual examination typically lasting 30 minutes or so.

Colon cancer can also be detected by using tests that examine stools, such as High-Sensitivity FOBT (Stool Test) and Fecal immunochemical test. These tests while less expensive and more convenient are not very effective in detecting colon cancer. In most cases, if cancer is detected using these tests, a confirmatory colonoscopy is often done.