Screening Methods For Colorectal Cancer

Screening Methods For Colorectal Cancer
17 Mar 2023
8 mins
Table Of Content
Screening Methods For Colorectal Cancer

    Worldwide, 3.2 million new cases and 1.6 million deaths are predicted to occur in 2040 because of colorectal cancer screening. 10.5% of newly diagnosed cases of colorectal cancer occur in patients under the age of 50. Each year, colorectal cancer is believed to be the root cause of 50,000 mortality. But if we discover the early symptoms of colon cancer, it can be treated easily. Welcome back to today's blog; since march is the awareness month for colorectal cancer. We are here to gather more knowledge on colorectal cancer screening and its risk in today's blog. 

    What Is Colorectal Cancer? 


    Colorectal cancer is described by uncontrolled cell growth in the colon or rectum. Mostly it develops as a tumor on the lining of the colon or rectum. Based on their initial development, these tumors may also be called rectal or colon cancer. Rectal and colon cancer are frequently combined because they have many features in common; The large intestine is also called a large bowel; hence colorectal cancer is also known as bowel cancer. Early symptoms of colon cancer include changes in bowel habits, rectal bleeding or blood in stool, weakness or fatigue, and sudden weight loss. 


    Role Of Polyp In Developing Cancer 


    Colon cancer typically spreads slowly; it can be round or appear like small mushrooms growing from stalks. A polyp is a medical term for the irregular growth of cells in the colon or rectum. This polyp can potentially develop into cancer cells in the progressive stage. Normally, a polyp grows for ten years before it develops cancer and spreads. If a polyp is found during a colorectal cancer screening, your doctor could advise increasing the frequency of screenings.


    Screening Test For Colorectal Cancer 

    According to studies, several colorectal cancer screening procedures contribute to the early detection of the disease and may reduce mortality. When a person does not show any early symptoms of colon cancer, tests are performed to examine various types of cancer. Five types of screening tests are used to identify colorectal cancer


    • Fecal occult blood test
    • Sigmoidoscopy
    • Colonoscopy
    • Virtual colonoscopy
    • DNA stool test.

    Fecal Occult Blood Test (FOBT) 


    To screen for hidden (occult) blood in the stool (poop), FOBT is used. The test can find small amounts of blood that can be seen with the microscope. A small feces sample is placed on a special card or in a special container for testing. Blood in the stool may indicate cancer, polyps, or other diseases. It helps medical professionals in the diagnosis of several problems. There are three types of FOBT:


    • Guaiac fecal occult blood test (gFOBT): gFOBT detects occult blood in the stool on the special card using a chemical called guaiac. The color of the special card changes if there is blood in the stool.
    • Fecal immunochemical test (iFOBT or FIT):  The stool sample mixture is injected into the machine that contains antibodies that can trace the blood in the stool sample. A line appears in the machine if there is the presence of blood.
    • FIT-DNA checks for genetic defects (DNA alteration) linked to colorectal cancer.



    A sigmoidoscope is a small, tube-shaped device with a monitoring lens and light. Sigmoidoscopy examines the rectum and sigmoid (lower) colon for polyps, aberrant tissue, or cancer. Via the rectum and into the sigmoid colon, a sigmoidoscope is inserted. Moreover, it may have a tool for removing polyps or tissue samples examined under a microscope for signs of rectal cancer. 


    The procedure looks inside the large intestine, which contains the colon, rectum, and anus. The colonoscope enters the colon after passing into the rectum and anus. Images of the interior of your large intestine are transmitted to a screen along the way. It may have a tool for removing polyps or tissue samples examined under a microscope for signs of rectal cancer.

    Virtual Colonoscopy


    This procedure uses a series of x-rays called computed tomography to produce a sequence of colon images. A computer combines the photos to produce detailed images that could reveal polyps and other abnormalities on the colon's inside surface. The other name of this test is CTC or computed tomography colonography. 

    DNA Stool Test


    This test looks for DNA alterations in a stool sample that could indicate colorectal cancer. If no DNA alteration and no signs of blood are found in the stool, then the test is considered negative. 

    Does Colon Cancer Screening Test Have Risk? 

    Various screening procedures carry different risks or concerns, like receiving false negative and positive results. Discuss the necessity for colon cancer screening and your risk for colorectal cancer with your doctor.

    • Colonoscopy causes bleeding and tears in the colon's lining. Sedation is used to decrease the discomfort of this procedure which can cause heart disorders and lung diseases such as irregular heartbeat or shortness of breath.
    • Even though sigmoidoscopy causes tears in the lining of the colon, it has fewer complications than a colonoscopy because no sedation is used in this process.
    • Virtual colonoscopy frequently identifies issues with organs other than the colon, such as the pancreas, spleen, liver, kidneys, chest, and ovaries.
    • Even if no cancer is identified, the findings of an FOBT or DNA stool test may seem abnormal. A positive test result might require more testing.

    “A good doctor cures the disease, but a great doctor cures the cause.”

    Screening saves a life. Since March is celebrated as national colorectal cancer awareness month, this blog aims to educate everyone about colorectal cancer screening. Wearing a blue ribbon spreads more awareness of the warning signs of colon cancer and its screening procedure, which can save human life. We are at the end of today's blog. Hope we have educated ourselves on the screening test for colorectal cancer. Let's promise that we will speak about screening tests and make everyone aware. Remember, prevention is far better than cure.

    Written by
    Dr. Karpagam AnandMedical Content Writer
    AboutPharm D
    Tags :Screening of colorectal cancerColon cancer screening testMethods of screening test for colon cancerColorectal cancer screening test