Navigation Links
Colon cancer screening: Immunological tests are superior

For early detection of colorectal (colon) cancer, statutory health insurance in Germany offers a fecal occult blood test free of charge to all insured persons starting at 50 years of age. In addition, those 55 or older are entitled to an endoscopic examination of the colon (colonoscopy). Colonoscopy identifies precancerous lesions with a high level of exactitude. Nevertheless, only about 20-30 percent of those eligible actually take advantage of the screening examination. "Therefore, fecal occult blood tests are important, because they help us reach more people. People are much more willing to have a simple laboratory test. Hence it is all the more important for these tests to provide valuable results," says Professor Hermann Brenner from the German Cancer Research Center (Deutsches Krebsforschungszentrum, DKFZ).

The test covered by health insurance is based on the detection of enzymatic activity in fecal occult blood (a "stool guaiac test"). For several years now, immunological testing methods using antibodies to detect hemoglobin in stool samples have also been available. These tests are regarded as more sensitive; i.e., they are believed to detect more tissue abnormalities. Until now, however, the two methods have only been compared in a few small-scale studies.

Hermann Brenner and his coworker Sha Tao have now directly compared the two methods in a large-scale study for the first time. 2,235 participants who underwent colon cancer screening colonoscopies between 2005 and 2009 provided stool samples immediately prior to the examination. These were tested for occult blood using both methods. Subsequently, the DKFZ researchers analyzed the test results by comparing them with the results from colonoscopies.

The enzyme-based test detected one third of all colon cancer cases, about nine percent of advanced precancerous lesions (adenomas), and about five percent of early precancerous lesions. The specificity was slightly over 95 percent: In 95 out of 100 participants with negative test results, no tissue abnormalities were found in the subsequent colonoscopy.

However, the three immunological tests* that were used detected about twice as many cancer cases (60.0, 53.3 and 73.3 percent) and about three times as many advanced precancerous lesions, with a specificity that was a little higher than enzymatic testing.

Only one third (31 percent) of all positive results from enzymatic testing were in fact the result of a tissue abnormality. By contrast, colonoscopy confirmed the presence of an abnormality in about two thirds (57 to 68 percent) of positive results obtained by immunological testing. "Immunological tests can thus help encourage people with a positive finding to undertake a colonoscopy afterwards, meaning that those individuals who actually have precancerous lesions would likely participate in colonoscopy screening," explains Brenner.

The enzymatic test only provides a positive or negative result, whereas the immunological test quantifies hemoglobin levels. The researchers therefore had to make the results comparable by defining threshold values for the immunological tests such that both methods delivered the same number of positive results.

"For the first time we have shown by direct comparison that the diagnostic performance of immunological stool tests is significantly higher than that of the enzymatic test at the same rate of positive results," says Hermann Brenner. He hopes that his research will provide a convincing argument to health-care policy makers. "Tests for occult blood in the stool will continue to be an important part of colon cancer screening. We therefore recommend including immunological tests in cancer screening programs in Germany. Many more people would thus benefit by obtaining a life-saving clue pointing to a hidden case of cancer."

In a number of European countries that offer cancer screening programs, immunological tests have already become the standard. Besides higher sensitivity, they offer further practical advantages: They can be more easily automated, and participants do not have to avoid certain types of food prior to the test, because the antibodies react specifically to human hemoglobin. Brenner is convinced that the slightly higher costs of immunological testing will fall once the tests can be produced on a large scale.


Contact: Dr. Sibylle Kohlstädt
Helmholtz Association of German Research Centres

Related medicine news :

1. hCGTreatments/Diet Doc hCG Diet & Weight Loss Plans Now Teach Patients How to Lose Weight Safely and Offer Alternative to Weight Loss Surgery Now Linked to Colon Cancer
2. New Device May Show Doctors More of the Colon
3. New smartphone application improves colonoscopy preparation
4. New colonoscope provides ground-breaking view of colon
5. The Surgeons of Los Angeles Colon and Rectal Surgical Associates are Now Offering Exparel for Use in Local Anesthesia During Anorectal Operations
6. Sea Colony Tennis Center Announces May and June USTA Sponsored Events
7. Sea Colony Ranked No. 15 Tennis Camp in the World by Tennis Resorts Online
8. Women Smokers More Likely to Get Colon Cancer Than Men: Study
9. Women smokers may have greater risk for colon cancer than men
10. Calcium May Cut Risk for Precancerous Colon Lesions in Some People
11. New Article Detailing Probiotics for Gut and Colon Health Published by eProbiotics
Post Your Comments:
(Date:6/25/2016)... ... 2016 , ... Austin residents seeking Mohs surgery services, can now turn to ... Dr. Russell Peckham for medical and surgical dermatology. , Dr. Dorsey brings specialization to ... fellowship in Mohs Micrographic Surgery completed by Dr. Dorsey was under the direction of ...
(Date:6/25/2016)... California (PRWEB) , ... June 25, 2016 , ... "With ... fit their specific project," said Christina Austin - CEO of Pixel Film Studios. ... customizable and all within Final Cut Pro X . Simply select a ProHand ...
(Date:6/25/2016)... Long Beach, CA (PRWEB) , ... June 25, 2016 , ... ... from UCLA with Magna Cum Laude and his M.D from the David Geffen School ... San Diego and returned to Los Angeles to complete his fellowship in hematology/oncology at ...
(Date:6/25/2016)... ... June 25, 2016 , ... On Friday, June 10, ... Bronze Wellness at Work award to iHire in recognition of their exemplary accomplishments in ... the 7th annual Maryland Workplace Health & Wellness Symposium at the BWI Marriott in ...
(Date:6/24/2016)... ... ... A recent article published June 14 on E Online details ... to state that individuals are now more comfortable seeking to undergo not only the ... and cheek reduction. The Los Angeles area medical group, Beverly Hills Physicians (BHP) notes ...
Breaking Medicine News(10 mins):
(Date:6/24/2016)... , June 24, 2016   Pulmatrix, Inc ... company developing innovative inhaled drugs, announced today that it ... Russell Investments reconstituted its comprehensive set of U.S. ... "This is an important milestone for Pulmatrix," said ... increase shareholder awareness of our progress in developing drugs ...
(Date:6/23/2016)... Research and Markets has announced the addition of ... report to their offering. ... kidney failure, it replaces the function of kidneys by removing ... thus the treatment helps to keep the patient body,s electrolytes ... Increasing number of ESRD patients & substantial healthcare expenditure ...
(Date:6/23/2016)... -- Roche (SIX: RO, ROG; OTCQX: RHHBY) announced that ... PCT (procalcitonin) assay as a dedicated testing solution for ... clearance, Roche is the first IVD company in the ... risk assessment and management. PCT is a ... in blood can aid clinicians in assessing the risk ...
Breaking Medicine Technology: