Colonoscopy Versus  Other Colon Cancer Screens

What is a Colonoscopy? Colonoscopy Procedure Information:
 as the word says, means “to look inside the colon”. Doctors guide a scope trough the patient’s entire colon to check for abnormalities. The scope inflates the large intestine with carbon dioxide gas to give the doctor a better view. The thin, flexible tube (scope) has a light and a small camera on the tip which transmits a video image from inside the large intestine to a Monitor. Various miniaturized tools can be inserted through the scope to obtain biopsies (samples) from abnormal-looking tissues of the colon and allow for a variety of choices to help diagnose or treat conditions. When used as a colon cancer prevention method, colonoscopy can find potentially precancerous growths called polyps and remove them during the procedure before they turn into cancer. That is why Doctors consider colonoscopy the gold standard for detecting polyps that can lead to colon cancer as well as for the cancer itself making colonoscopy an invaluable tool that helps your doctor answer important questions about your digestive health and prevent certain diseases like colon cancer.

coloncancerscreeningmethods Many people avoid the colonoscopy procedure because of discomfort and a small risk of complications.
Virtual colonoscopy also known as CT colonography (CTC) is nearly as accurate as the real thing, and has in the past few years begun to catch on. It uses special software to view CT scans of a patient’s colon and allows doctors to see colon polyps before they become deadly colon cancers. Even though this test is not as invasive like a colonoscopy, CTC is a diagnostic procedure only, a possible drawback. It requires the same type of bowel preparation as in a conventional colonoscopy and should any suspicious polyps be found by CTC, they will have to be removed by or explored further with a conventional colonoscopy, potentially exposing the patient to unpleasant procedures twice.

Colonoscopy Prep: Colonoscopy Preparation:
Bowel preparation
or colonoscopy prep is to eliminate all fecal matter from the colon so that the physician conducting the CT colonography or colonoscopy will have a clear view.

Flexible sigmoidoscopy is similar to colonoscopy, but it only examines the lower third of the colon (large intestine). As a result, any cancers or polyps farther into the colon can’t be detected with flexible sigmoidoscopy. A flexible sigmoidoscopy exam however can help your doctor explore possible causes of abdominal pain, rectal bleeding and change in bowel habits, chronic diarrhea and other intestinal problems.

Stool sample testing: Both FOBT (Fecal Occult Blood Test) and FIT (Fecal Immunochemical Test) look for hidden blood in the stool. Occult or hidden blood can be an early sign of colon cancer.

Colonoscopies, Real and Virtual, Outperform Other Tests
A study, presented in 2008 at the annual Gastrointestinal Cancers Symposium, by a German research team led by University of Munich’s Frank Kolligs, MD involved 307 men and women aged 50 or older. None of which had had symptoms of colon cancer.

Stool samples were collected for FOBT (Fecal Occult Blood Test) and FIT (Fecal Immunochemical Test). Patients took colonoscopy and CT colonography (CTC) on the same day, facilitating same day bowel preparation. By counting lesions found in the lower third of the colon in a colonoscopy, the researchers estimated results of a sigmoidoscopy.

Colonoscopy and Virtual Colonoscopy detected advanced adenomas (growths which could become malignant) with similar results. Both tests detected polyps larger than 10 millimeters (3/8”), a size considered unsafe at basically the same rate. Colonoscopy found far more tiny polyps, 5 millimeters (3/16”) or smaller than did CTC, but such polyps are very rarely malignant.

Sigmoidoscopy, found about two-thirds of colon growths. FIT detected fewer than half of growths, while FOBT only found about one-fifth.

FOBT gave false-positive results to 10 percent of people who didn’t have the dangerous growths. The comparable figure for FIT testing was 14 percent.
Dr. Kolligs says that combining the results of various tests such as sigmoidoscopy plus FOBT, sigmoidoscopy plus FIT, and FOBT plus FIT, resulted in “no or only slightly increased rates of detection over one test alone.” He went on to say that “doctors thought FIT, which directly measures a component of blood called hemoglobin in the stool, would prove more accurate than FOBT, which indirectly measures hemoglobin, but that didn’t prove to be the case”.

Says Richard Schilsky, MD, a professor of medicine and associate dean for clinical research, Biological Sciences Division, University of Chicago Pritzker School of Medicine, and specialist in gastrointestinal cancers. ”Although while his institution the University of Chicago Medical Center, an Illinois Hospital  has virtual reality as an option for patients who might prefer not have a colonoscopy; he still recommends his patients have the real thing, for the simple reason that any polyps that are found via colonoscopy can be immediately removed. Patients who have suspicious polyps found by CTC must still undergo colonoscopy to have them taken out.

Dr. Schilsky also led a groundbreaking study, which found that aspirin reduces the incidence of pre-cancerous polyps in patients at high risk for colorectal cancer.

You should also be informed about the types of sedation that are available for colonoscopies and you may want to read the article colonscopy sedation without versed so that you can have a discussion with your gastroenterologist about the types of sedation options that are available and that you wish to have used during your procedure.