5 Things About Colorectal Screening That You Must Know

September 7, 2018

With cases of colon cancer in Singapore on the rise, going for regular screening programs is crucial to help in an early detection of the cancer. Colon cancer, which also can be referred to as colorectal cancer, rectal cancer or bowel cancer, is the most common cancer affecting men and second most common cancer affecting women.

Stool test to look for microscopic blood, also known as FIT (fecal immunochemical test) is being used to screen for colorectal cancer nationwide. It is cheap and easily available. Singapore Cancer Society, through their cancer screening program, provides the kits free of charge. It is also available at very low cost at most family physicians’ clinic and polyclinics.

Anyone found with a positive FIT would then be advised to go for a colonoscopy. This strategy is proven to lower the cancer related death in the population. However, there are some facts that are really important to know regarding colorectal screening.

Colonoscopy Is Still Better

Each FIT only has a sensitivity of about 20-30% for detecting large polyps and about 80% for detecting colorectal cancer. In other words, if you only do FIT once, at least 7 out of 10 big polyps would not be detected and two out of ten cancer would be missed. This is is stark contrast with colonoscopy: All large polyps and colorectal cancers are expected to be diagnosed with a single colonoscopy done by a well trained gastroenterologist. The main reason preventing colonoscopy from being recommended as the main strategy is the cost involved.

Water-Assisted Colonoscopy

It is a new technique of doing colonoscopy, where water instead of air or CO2 is used to facilitate insertion of colonoscope into the colon. Water-assisted colonoscopy is more comfortable and it reduces the need for sedative medication and adds to the safety of colonoscopy.

Using Cold Snare For Polypectomy

The risk of perforation (causing a hole in the colon) reduces significantly when the gastroenterologist use cold snare to remove small polyps. This is a newer approach that is advocated by major professional bodies governing the use of colonoscopy world wide.

The Skills Of The Person Doing The Colonoscopy Matters The Most

This is highlighted repeatedly in all major guidelines governing the use of colonoscopy as a screening tool for colorectal cancer. The specialist that is trained specifically to do endoscopy including colonoscopy is called a gastroenterologist. The gastroenterologist should have a high volume of colonoscopy, a very short average cecal intubation time (<5 minutes), at least 6 minutes in withdrawal time and have at least 25% adenoma detection rate.

When Should I Go For Colorectal Screening?

For a while the recommendation is for an average risk person is to start screening at age of 50. This guideline has recently been changed in the United State and the age to start screening has been lowered to 45 because the age of onset of colorectal is decreasing over time. The recommended age to start screening is a balance between case detection and cost of screening. If cost is not an issue, screening can be done earlier. health screening is not complete without colorectal screening for most individual. For those with a higher risk of colorectal cancer, including people with family history and certain colon conditions, there should consult with doctors regarding the optimum age to begin screening.