Colorectal Cancer Diagnosis

Colorectal Cancer - Diagnosis

There are several different tests that can be used to detect polyps, cancer or other abnormalities in the colon and rectum. Before administering some of these tests, the colon must be emptied, and the doctor may prescribe an enema or a liquid laxative. This preparation is very important in ensuring the test accuracy.

Diagnostic tests include:

Digital rectal examination

Often part of a routine physical examination during a clinical consult, the doctor checks the lower most area of the rectum by inserting a lubricated gloved finger into the rectum and gently feeling for abnormal growths. The exam may be uncomfortable but should not be painful.

Colonoscopy

Part of regular screening and diagnostic procedures, a colonoscopy examines the colon and rectum using a special flexible camera inserted through the anus. It allows the removal of small polyps and taking of tissue samples (biopsies) of any abnormal areas.

Computed Tomographic Colonography (CTC)

A CTC or virtual colonoscopy is a specific scan that creates a 3D image of the colon to reveal any abnormal masses. Images are taken seconds after the colon is inflated with carbon dioxide through a small rectal tube.

If diagnosed with colorectal cancer, the doctor may recommend further tests to determine the extent or stage of cancer. These are usually imaging tests for the abdominal, pelvic and chest areas.

In some cases, the extent of the cancer will only be known after surgery.

Colorectal Cancer – Staging

Stage 0 Carcinoma in situ – When there are abnormal or precancerous cells found in the mucosa, or innermost lining of the colon or rectum.

Stage 1 Colorectal Cancer – When cancer has spread into the deeper layers of the intestinal wall but does not extend beyond the muscle layer.

Stage 2 Colorectal Cancer - When cancer has penetrated deeper through or beyond the muscle layer of the intestine wall but has not spread to nearby lymph nodes.

Stage 3 Colorectal Cancer – When cancer has spread to the surrounding regional lymph nodes.

Stage 4 Colorectal Cancer – When cancer has spread or metastasised to areas beyond the colon or rectum and other organs such as the liver, lungs and perineum.