***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: BACKGROUND Faecal concentrations of the  protein calprotectin  have been found to be elevated in patients with colorectal neoplasia , suggesting that it might be used as a screening tool for colorectal cancer as well as adenomas . AIMS To measure the sensitivity and specificity of faecal calprotectin for the detection of adenomas in high risk individuals undergoing colonoscopy . Also , to investigate between and within stool variability of calprotectin concentrations . SUBJECTS A total of 814 patients planned for colonoscopy were included for the following indications : positive faecal occult blood test , 25 ; neoplasia surveillance , 605 ; newly detected polyp , 130 ; and family risk , 54 . METHODS Two faecal sample s from each of two stools were analysed using the PhiCal ELISA test device ( Nycomed Pharma AS ) . RESULTS Adenoma patients had significantly higher calprotectin levels than normal subjects ( median 9.1 ( 95 % confidence interval 7.5–10.1)v 6.6 (5.6–7.4)mg/l ) . There was no significant decrease in calprotectin levels after polypectomy . Levels in cancer patients were significantly higher than those in all other subgroups ( median 17.6 mg/l ( 11.5–31.0 ) ) . With a cut off limit of 10 mg/l , the sensitivity for cancer was 74 % and for adenoma 43 % . Corresponding specificity values were 64 % for no cancer and 67 % for no neoplasia ( cancer+adenoma ) . Specificity varied from 71 % for one stool sample to 63 % for four sample s. Stool variability was small , suggesting that two spots from one stool were as discriminative as two spots from each of two stools . CONCLUSIONS The sensitivity and specificity of faecal calprotectin levels as a marker for colorectal adenoma and carcinoma justifies its use in high risk groups , but specificity is too low for screening of average risk persons . Lack of a decrease in levels after polypectomy may be due to a more widespread leucocyte migration into the intestinal lumen than that at the polyp site , and needs further investigation BACKGROUND  Fecal calprotectin  is elevated in patients with colorectal cancer ( CRC ) . An improved method has been developed . The aim was to evaluate sensitivity and specificity for CRC with the new fecal calprotectin method and to compare the results with those of the original method . METHODS The study comprised 453 subjects including symptomatic CRC patients and CRC high risk subjects with and without CRC .  Complete colonoscopy was performed .  Calprotectin  was measured with an enzyme linked immunosorbent assay ( ELISA ) using small ( 50 - 100 mg ) feces sample s. RESULTS Fecal calprotectin levels were significantly elevated in symptomatic CRC and in asymptomatic CRC detected in high risk subjects . Calprotectin levels were significantly decreased 3 months after cancer removal . A cut-off limit of 50 microg/g result ed in a sensitivity of 89 % in CRC patients and 79 % in high risk subjects , compared to 89 % and 75 % , respectively , with the original method , using 10 mg/l as cut-off limit . Specificity was improved with the new method to 68 % and 91 % at cut-off of 50 and 150 microg/g , compared to 66 % and 88 % , respectively . Negative predictive value ( NPV ) was 99 % for cut-off of 50 microg/g in the high risk population . One stool sample was sufficient , but measurement of two spots in two stools increased sensitivity to 98 % for symptomatic and 82 % for asymptomatic CRC . CONCLUSION The new simple method , using small sample s of feces , had a higher diagnostic accuracy , suggesting that it should be preferred to the original one , in screening high risk groups for CRC OBJECTIVES : Stool testing is a well established method of screening for colorectal neoplasia . Emerging data suggest that novel biomarkers may offer performance advantages over fecal occult blood . In this large , prospect i ve study , we assessed fecal calprotectin ( a leukocyte-derived protein ) as a screening biomarker for colorectal neoplasia . Fecal calprotectin was directly compared to fecal hemoglobin ( Hb ) and colonoscopy as the existing criterion st and ards for stool screening and structural evaluation , respectively . METHODS : Subjects included colonoscopy patients with a personal history of colorectal neoplasia , family history of colorectal cancer , or iron deficiency anemia . Stool specimens were collected before purgation , processed appropriately , and quantitatively analyzed for calprotectin ( Nycomed Pharma , Oslo , Norway ) and for Hb ( Mayo Medical Laboratories , Rochester , MN ) by masked technicians . Colonoscopies were performed by experienced endoscopists without prior knowledge of the fecal assay results . RESULTS : Among 412 subjects , 97 ( 24 % ) subjects had one or more colorectal neoplasms ( including three with adenocarcinomas ) .  Fecal calprotectin levels did not differ significantly between subjects with versus subjects without colorectal neoplasms ( p= 0.33 ) . Neither tumor number ( p= 0.85 ) nor tumor size ( p= 0.86 ) significantly influenced the observed fecal calprotectin concentrations . Estimates of the sensitivity , specificity , and positive and negative predictive values of fecal calprotectin for any colorectal neoplasms were 37 % , 63 % , 23 % , and 76 % , respectively . Comparable performance estimates for fecal Hb were 3 % , 97 % , 27 % , and 77 % , respectively . CONCLUSIONS : In this cohort of colonoscopy patients at above average risk , fecal calprotectin was a poor screening biomarker for colorectal neoplasia . Further investigation of tumor-derived , rather than blood-based , biomarkers may be a more rewarding approach to stool screening for colorectal neoplasia Background : Screening for colorectal cancer ( CRC ) using guaiac based faecal occult blood tests ( FOBT ) has an estimated programme sensitivity of > 60 % but < 30 % for strictly asymptomatic CRC in a single screening round . In search for improved non-invasive tests for screening , we compared a test for faecal calprotectin ( PhiCal ) with a human haemoglobin immunochemical FOBT ( FlexSure OBT ) . Methods : In the Norwegian Colorectal Cancer Prevention ( NORCCAP ) trial , screenees in one screening arm were offered screening with combined flexible sigmoidoscopy ( FS ) and FlexSure OBT . They were also requested to bring a fresh frozen sample of stool for the PhiCal test which was performed on sample s from screenees with CRC ( n = 16 ) , high risk adenoma ( n = 195 ) , low risk adenoma ( n = 592 ) , and no adenoma ( n = 1518 ) ( 2321 screenees in total ) . A positive PhiCal test was defined by a calprotectin level ⩾50 μg/g . Results : The PhiCal test was positive in 24–27 % of screenees whether they had no adenoma , low risk adenoma , or high risk adenoma . Ten ( 63 % ) of 16 CRCs gave a positive PhiCal test . The total positivity rate in this population was 25 % for the PhiCal test compared with 12 % for FlexSure OBT , with a sensitivity for advanced neoplasia of 27 % and 35 % , respectively . Specificity for “ any neoplasia ” was 76 % for the PhiCal test and 90 % for FlexSure OBT . Conclusions : In colorectal screening , the performance of the PhiCal test on a single spot from one stool sample was poorer than a single screening round with FlexSure OBT and can not be recommended for population screening purpose s. The findings indicate a place for FlexSure OBT in FOBT screening Fecal  calprotectin ( CPT )  is elevated in the majority of patients with known colorectal cancer ( CRC ) , but the specificity is not clarified . Aim : To evaluate if a CPT test ( PhiCal ELISA ) was more sensitive than Hemoccult II test in detecting colorectal neoplasia , and to obtain reference values in subjects with normal colonoscopy . To evaluate a possible relation between number and extent of dysplasia of adenomas in first degree relatives of patients with CRC and the stage of the carcinoma in the index casus . Further to study the prevalence of CRC and adenomas in the first degree relatives of patients operated for CRC . Method : In a multicenter study , 253 first degree relatives of patients with CRC , aged 50–75 years ( mean age 60 years ) underwent colonoscopy after having delivered stool sample s and three Hemoccult II slides . Results : In 237 first degree relatives from 148 patients with CRC , polyps were found in 118 ( 50 % ) . Seventy three ( 31 % ) had adenomas and 17 had adenomas ≧10 mm . Five had asymptomatic cancers . The specificity of fecal CPT for adenomas at cut off levels ≤10 , ≤15 and ≤20 mg/l were 47.4 , 59.6 and 71.1 % , respectively ( max of three sample s ) . The sensitivity at same cut off levels was 56.2 , 45.2 and 31.5 % and 4/5 of patients with carcinoma had CPT values > 15 mg/l . The sensitivity of Hemoccult II  for adenomas was 8 % , and 4/5 of patients with carcinoma had negative Hemoccult II . The specificity for adenomas was 95 % . Conclusion : Fecal CPT test was more sensitive  than Hemoccult II in detecting colorectal neoplasia but the specificity was lower . In a high risk group like first degree relatives of patients with CRC , there are good reasons to consider fecal CPT as a first test in selecting patients for endoscopy 
    Output:
    
RESULTS According to the literature ,  calprotectin  seems to be a reliable sensitive marker in the diagnosis and postoperative evaluation of CRC patients at the cost of low specificity and no correlation with the progress and stage of disease .
Calprotectin st and s for a novel but well-evaluated biomarker in CRC .
The experimental studies focus on the CRC microenvironment and suggest that malignant cells and tissues overexpress S100A8 and S100A9 and the heterodimer S100A8/A9