RT Journal Article SR Electronic T1 OC-071 Comparison of Faecal M2-PK and Fit in Screening for Colonic Polyps in an average Risk Population JF Gut JO Gut FD BMJ Publishing Group Ltd and British Society of Gastroenterology SP A30 OP A31 DO 10.1136/gutjnl-2013-304907.070 VO 62 IS Suppl 1 A1 Leen, R A1 Shearer, N A1 O’Morain, C A1 McNamara, D YR 2013 UL http://gut.bmj.com/content/62/Suppl_1/A30.3.abstract AB Introduction Faecal immunochemical tests (FIT) are acceptable to a large part of the general population but used alone are poor at detecting adenomas. An ELISA which measures faecal M2-pyruvate kinase (M2-PK) has been shown to be useful for detecting colonic pathology. Aims To prospectively compare M2-PK and FIT in screening for colonic polyps and cancer in the second round of our pilot FIT-based Colorectal cancer screening programme. Methods The second round of our FIT pilot programme was conducted over a two year period. Patients were sent invites by post to return a FIT sample from each of two days. All participants were aged 50 – 74 and living locally to our hospital. As part of this round, over a six month period all invitations additionally included containers to collect a single M2-PK stool sample. All FIT’s returned on time were measured locally. All M2-PK samples received within 48 hours of passing stool were frozen and analysed centrally by ScheBo Biotech AG (Germany). All FIT positive (>100 ngHb/ml) or M2-PK positive (>4 U/ml) patients were contacted and assessed for colonoscopy. All colonoscopies were conducted in the same way between both groups. Results Over the six month period 1,800 combined M2-PK and FIT invites have been sent. 879 samples were returned and analysed for faecal M2-PK and FIT; of these 245 were positive for either one or both of these markers. After being contacted 34 (13%) of this group were excluded as they had a colonoscopy within 3 years and were all in polyp surveillance programmes. Of the remaining patients: 30 (3.4% of 879) were FIT positive M2-PK negative; 160 (18.2%) were positive for M2-PK ( > 4U/ml) negative for FIT and 21 (2.3%) were positive for both markers. In the FIT positive M2-PK negative group there were 10 patients with adenomas (adenoma detection rate 33%). In those who were M2-PK positive but FIT negative there were 34 people with adenomas (ADR 23%). Therefore these adenomas would not have been detected by relying on FIT alone. Of the remaining 21 positive for both, 6 (29%) had adenomas and another 4 (19%) had colitis/proctitis. There have not been any cancers in this group to date. Interestingly sessile serrated adenomas were detected in 5 (4.4%) of people M2-PK positive but only two (less than 1%) in our entire FIT positive group. Conclusion Studies have shown FIT has relatively low sensitivity for adenomas. The addition of another stool marker such as faecal M2-PK increases the detection of polyps in a screening population. A single M2-PK sample detects more adenomas than two day FIT alone. Also M2-PK appears to be more sensitive for serrated adenomas than FIT but further studies are needed to confirm this. Disclosure of Interest None Declared