***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Context Several immunochemical fecal occult blood tests ( FOBTs ) that use different antibodies against human blood components are available . Contribution This study compared characteristics of 6 qualitative immunochemical FOBTs and 1 guaiac-based FOBT to identify adenomas among adults who attended screening colonoscopy .  The FOBTs had widely varying performance characteristics . Sensitivity and specificity for detecting advanced adenomas ranged from 25 % to 72 % and 70 % to 97 % , respectively , for the immunochemical tests and were 9 % and 96 % , respectively , for the guaiac test . Caution One-day stool sample s were used , and stool was frozen before testing . Implication Qualitative immunochemical FOBTs have varying performance characteristics for detecting precancerous colorectal lesions . The Editors Colorectal cancer ( CRC ) is the third most common cancer in the world ( 1 ) , with about 1 million new cases and more than 500000 deaths per year . Because most cases of CRC are sporadic and develop from removable precancerous lesions ( adenomas ) and curable early- stage cancer ( 2 ) , screening for CRC has high potential for reducing morbidity and mortality . R and omized , controlled trials have demonstrated reduced mortality with guaiac-based fecal occult blood testing ( FOBT ) followed by colonoscopy or sigmoidoscopy if the FOBT result is positive ( 3 ) . However , guaiac-based FOBT , which detects the pseudoperoxidase activity of heme or hemoglobin , has important limitations . It is not specific for human hemoglobin , and false-positive and false-negative results can result from certain compounds or medications in foods ( for example , red meat or vitamin C ) ( 4 ) that should be avoided during the days before testing . Another important limitation is the low diagnostic performance for precursors to CRC . An advantage of guaiac-based FOBT is the simple analysis , which can easily be done at the physician 's office , even though reliable interpretation of test results requires training ( 5 , 6 ) . Immunochemical FOBTs that use specific antibodies against human blood components overcome the problem of diet or medication restriction . Unlike quantitative immunochemical FOBTs , qualitative immunochemical FOBTs that mostly use immunochromatographic technology also allow simple , office-based analysis . However , there are differences among qualitative immunochemical FOBTs . For example , the antibodies used and the different detection limits may influence the diagnostic performance , especially with respect to detection of precursor lesions . We aim ed to determine and compare performance characteristics of different qualitative immunochemical FOBTs for the detection of colorectal adenomas in a large sample of women and men undergoing screening colonoscopy .  Methods Study Design and Sample The analyses were part of the BliTz study ( Begleitende Evaluierung innovativer Testverfahren zur Darmkrebsfrherkennung ) , an ongoing screening study conducted in cooperation with 20 gastroenterology practice s in southwestern Germany since January 2006 that aims to comparatively evaluate new tests for early detection of CRC . The study includes participants undergoing screening colonoscopya procedure that the German health care system has offered since October 2002 to average-risk persons 55 years or older . In Germany , preliminary consultation for any type of cancer screening is mostly done by general practitioners . For screening colonoscopy , patients are referred to the gastroenterologist only when the decision to have colonoscopy is made . All participants had a preliminary consultation with a gastroenterologist to receive detailed information and advice about screening colonoscopy . They were informed about and invited to participate in the study at that time . After we received written informed consent , we asked patients scheduled for screening colonoscopy to provide a stool sample before bowel preparation . Physicians who did colonoscopy and histologic examination were blinded to FOBT results . After colonoscopy , we collected reports on colonoscopic and histologic findings and extracted information in a st and ardized manner while blinded to the results of stool testing . We did not query patients about adverse events of testing ( such as psychological distress ) . The ethics committee of the University of Heidelberg , Heidelberg , Germany , approved the study . We included patients who provided stool sample s for qualitative immunochemical FOBTs until 13 December 2007 . The Figure shows the numbers of all potentially eligible patients . Figure . Study flow diagram . FOBadv = FOB advanced ( ulti med , Ahrensburg , Germany ) ; FOBplus = Bionexia FOBplus ( DIMA , Gttingen , Germany ) ; Hb/Hp C = Bionexia Hb/Hp Complex ( DIMA ) ; HO = HemOccult ( Beckman Coulter , Krefeld , Germany ) ; immoCare = immoCARE-C ( CAREdiagnostica , Voerde , Germany ) ; PreventID CC = PreventID CC ( Preventis , Bensheim , Germany ) ; QuickVue = QuickVue iFOB ( Quidel , San Diego , California ) . * The exclusion of 44 patients overall was due to missing or noninterpretable test cards . Of 1785 patients undergoing screening colonoscopy who agreed to participate , 111 were excluded because of visible rectal bleeding or preceding positive FOBT result . We excluded 13 patients because of inflammatory bowel disease . These patients usually receive close colonoscopic surveillance and would not be regarded as the target population for primary FOBT screening . We excluded 117 patients because they had undergone colonoscopy in the past 5 years and thus would not be eligible for primary FOBT screening  ( if the previous colonoscopy result was positive , they are recommended for colonoscopic surveillance ; if the result was negative , they are at very low risk for colorectal neoplasia ) . We further excluded participants whose stool sample s were collected after colonoscopy only ( and thus violated the study protocol [ n= 65 ] ) , those with inadequate bowel preparation before colonoscopy ( n= 79 ) , and those with incomplete colonoscopy ( that is , the cecum was not reached , [ n= 22 ] ) . We excluded patients who received a histologically confirmed diagnosis of CRC ( this subgroup comprised only 11 participants by the end of 2007 and would not allow meaningfully precise performance estimates for this end point ) . Sensitivity with respect to CRC will be analyzed separately after continued recruitment of a much larger number of screening participants . We excluded 10 participants with nondefined polyps ( no histologic reports were available ) because we could not definitively determine the presence or absence of advanced adenomas in this group . Finally , we excluded participants with pseudopolyps ( n= 38 ) because these patients probably have had ulcerative colitis or undocumented inflammatory bowel disease . Stool Sample Collection Participants undergoing screening colonoscopy  typically present at the gastroenterology practice for preliminary consultation about 1 week before colonoscopy . At that time , eligible patients received a study package that contained 1 test card for guaiac-based FOBT ( HemOccult , Beckman Coulter , Krefeld , Germany ) , a small container ( 60 mL ) for stool collection , a collection tissue for avoiding contact of the stool with toilet water , and detailed instructions for stool collection . Stool sample s were collected at home with no specific recommendations for diet or medicine restrictions . Patients received detailed instructions for sampling : Collect 1 bowel movement by using the collection tissue ; apply stool with a spatula ( provided in the study package ) on 2 windows of 1 HemOccult test card and store the test card at room temperature ; and fill at least half of the small container with stool by using plastic spoons ( provided in the study package ) , and store a plastic bag with the container in the freezer or , if not possible , in the refrigerator . Although the amount of stool provided varied widely , sufficient stool was available to adequately perform the different tests in all cases . On the day of colonoscopy , patients provided the HemOccult test card and the stool-filled container at the gastroenterology practice . The latter was stored at 20C , then shipped on dry ice to a central laboratory and stored at 20C until analysis . We documented the date s of stool sampling , arrival at the central laboratory , and performance of the immunochemical FOBTs . Laboratory Analyses Physician assistants who were blinded to the results of immunochemical testing  analyzed HemOccult test cards at the gastroenterology practice on receipt according to the manufacturer 's instructions . They did analyses of HemOccult without rehydration , and test results were classified as positive , negative , or not interpretable ( for example , owing to incorrect sampling ) . We thawed the stool-filled containers at a median interval of 4 days on arrival at the central laboratory to do qualitative immunochemical FOBTs . Overall , we did 5 tests to determine fecal hemoglobin levels ( Bionexia FOBplus , DIMA , Gttingen , Germany ; PreventID CC , Preventis , Bensheim , Germany ; immoCARE-C , CAREdiagnostica , Voerde , Germany ; FOB advanced , ulti med , Ahrensburg , Germany ; and QuickVue iFOB , Quidel , San Diego , California ) and 1 test to determine both fecal hemoglobin and hemoglobinhaptoglobin levels ( Bionexia Hb/Hp Complex , DIMA ) . All tests are based on immunochromatographic technology . The lower detection limits indicated by the manufacturers were 10 ng/mL ( PreventID CC ) , 25 ng/mL ( Bionexia Hb/Hp Complex ) , 40 ng/mL ( Bionexia FOBplus and FOB advanced ) , and 50 ng/mL ( immoCARE-C and QuickVue iFOB ) . We did all analyses according to the manufacturers ' instructions and under st and ardized conditions . One trained investigator who was blinded to colonoscopy and HemOccult results classified all test results as positive or negative . Although classification was sometimes difficult for borderline results , we did not use an additional category for such results because the distinction between these and positive or negative results would be similarly difficult and Introduction The Bowel Cancer Screening Programme in Engl and began operating in 2006 with the aim of full roll out across Engl and by December 2009 . Subjects aged 60–69 are being invited to complete three guaiac faecal occult blood tests ( 6 windows ) every 2 years . The programme aims to reduce mortality from colorectal cancer by 16 % in those invited for screening . Methods All subjects eligible for screening in the National Health Service in Engl and are included on one data base , which is populated from National Health Service registration data covering about 98 % of the population of Engl and . This analysis is only of subjects invited to participate in the first ( prevalent ) round of screening . Results By October 2008 almost 2.1 million had been invited to participate , with tests being returned by 49.6 % of men and 54.4 % of women invited . Uptake ranged between 55–60 % across the four provincial hubs which administer the programme but was lower in the London hub ( 40 % ) . Of the 1.08 million returning tests 2.5 % of men and 1.5 % of women had an abnormal test . 17 518 ( 10 608 M , 6910 F ) underwent investigation , with 98 % having a colonoscopy as their first investigation . Cancer ( n=1772 ) and higher risk adenomas ( n=6543 ) were found in 11.6 % and 43 % of men and 7.8 % and 29 % of women investigated , respectively . 71 % of cancers were ‘ early ’ ( 10 % polyp cancer , 32 % Dukes A , 30 % Dukes B ) and 77 % were left-sided ( 29 % rectal , 45 % sigmoid ) with only 14 % being right-sided compared with expected figures of 67 % and 24 % for left and right side from UK cancer registration . Conclusion In this first round of screening in Engl and uptake and fecal occult blood test positivity was in line with that from the pilot and the original European trials . Although there was the expected improvement in cancer stage at diagnosis , the proportion with left-sided cancers was higher than expected BACKGROUND An accurate , noninvasive test could improve the effectiveness of colorectal-cancer screening . METHODS We compared a noninvasive , multitarget stool DNA test with a fecal immunochemical test ( FIT ) in persons at average risk for colorectal cancer . The DNA test includes quantitative molecular assays for KRAS mutations , aberrant NDRG4 and BMP3 methylation , and β-actin , plus a hemoglobin immunoassay . Results were generated with the use of a logistic-regression algorithm , with values of 183 or more considered to be positive . FIT values of more than 100 ng of hemoglobin per milliliter of buffer were considered to be positive . Tests were processed independently of colonoscopic findings . RESULTS Of the 9989 participants who could be evaluated , 65 ( 0.7 % ) had colorectal cancer and 757 ( 7.6 % ) had advanced precancerous lesions ( advanced adenomas or sessile serrated polyps measuring ≥1 cm in the greatest dimension ) on colonoscopy .  The sensitivity for detecting colorectal cancer was 92.3 % with DNA testing and 73.8 % with FIT ( P=0.002 ) . The sensitivity for detecting advanced precancerous lesions was 42.4 % with DNA testing and 23.8 % with FIT ( P<0.001 ) . The rate of detection of polyps with high- grade dysplasia was 69.2 % with DNA testing and 46.2 % with FIT ( P=0.004 ) ; the rates of 
    Output:
    
Conclusions : Blood-based miRNAs distinguish patients with CRC from healthy controls with high sensitivity and specificity comparable to other common and invasive currently used screening methods for CRC .